Publications
Included in the list are the publications since 2011, authored by members of Department of Physics of Crystals and Department of Physics of Nanomaterials, which in 2019 merged into the Department of Physics of Nanostructures.
2014
89.
Michał Mruczkiewicz, Maciej Krawczyk
Nonreciprocal dispersion of spin waves in ferromagnetic thin films covered with a finite-conductivity metal Journal Article
In: Journal of Applied Physics, vol. 115, pp. 113909, 2014, (Copyright (2014) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Journal of Applied Physics 115, 113909 (2014); and may be found at http://scitation.aip.org/content/aip/journal/jap/115/11?ver=pdfcov).
@article{nonrecip_disp,
title = {Nonreciprocal dispersion of spin waves in ferromagnetic thin films covered with a finite-conductivity metal},
author = {Michał Mruczkiewicz and Maciej Krawczyk},
url = {http://scitation.aip.org/content/aip/journal/jap/115/11/10.1063/1.4868905},
doi = {dx.doi.org/10.1063/1.4868905},
year = {2014},
date = {2014-01-01},
journal = {Journal of Applied Physics},
volume = {115},
pages = {113909},
abstract = {We study the effect of one-side metallization of a uniform ferromagnetic thin film on its spin-wave dispersion relation in the Damon–Eshbach geometry. Due to the finite conductivity of the metallic cover layer on the ferromagnetic film, the spin-wave dispersion relation may be nonreciprocal only in a limited wave-vector range. We provide an approximate analytical solution for the spin-wave frequency, discuss its validity, and compare it with numerical results. The dispersion is analyzed systematically by varying the parameters of the ferromagnetic film, the metal cover layer and the value of the external magnetic field. The conclusions drawn from this analysis allow us to define a structure based on a 30 nm thick CoFeB film with an experimentally accessible nonreciprocal dispersion relation in a relatively wide wave-vector range.},
note = {Copyright (2014) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Journal of Applied Physics 115, 113909 (2014); and may be found at http://scitation.aip.org/content/aip/journal/jap/115/11?ver=pdfcov},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We study the effect of one-side metallization of a uniform ferromagnetic thin film on its spin-wave dispersion relation in the Damon–Eshbach geometry. Due to the finite conductivity of the metallic cover layer on the ferromagnetic film, the spin-wave dispersion relation may be nonreciprocal only in a limited wave-vector range. We provide an approximate analytical solution for the spin-wave frequency, discuss its validity, and compare it with numerical results. The dispersion is analyzed systematically by varying the parameters of the ferromagnetic film, the metal cover layer and the value of the external magnetic field. The conclusions drawn from this analysis allow us to define a structure based on a 30 nm thick CoFeB film with an experimentally accessible nonreciprocal dispersion relation in a relatively wide wave-vector range.
88.
Michał Mruczkiewicz, E S Pavlov, S L Vysotsky, Maciej Krawczyk, Yu A Filimonov, S A Nikitov
Observation of magnonic band gaps in magnonic crystals with nonreciprocal dispersion relation Journal Article
In: Physical Review B, vol. 90, pp. 174416, 2014, (Copyright (2014) American Physical Society (APS). This article may be downloaded for personal use only. Any other use requires prior permission of the author and the APS. The following article appeared in Phys. Rev. B 90, 174416 (2014); and may be found at http://journals.aps.org/prb/abstract/10.1103/PhysRevB.90.174416).
@article{nonreciprocal_dispersion,
title = {Observation of magnonic band gaps in magnonic crystals with nonreciprocal dispersion relation},
author = {Michał Mruczkiewicz and E S Pavlov and S L Vysotsky and Maciej Krawczyk and Yu A Filimonov and S A Nikitov},
url = {https://journals.aps.org/prb/abstract/10.1103/PhysRevB.90.174416},
doi = {10.1103/PhysRevB.90.174416},
year = {2014},
date = {2014-01-01},
journal = {Physical Review B},
volume = {90},
pages = {174416},
note = {Copyright (2014) American Physical Society (APS). This article may be downloaded for personal use only. Any other use requires prior permission of the author and the APS.
The following article appeared in Phys. Rev. B 90, 174416 (2014); and may be found at http://journals.aps.org/prb/abstract/10.1103/PhysRevB.90.174416},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
87.
Andriy E Serebryannikov, S Nojima, E Ozbay
One-way absorption of terahertz waves in rod-type and multilayer structures containing polar dielectrics Journal Article
In: Physical Review B, vol. 90, pp. 235126, 2014, (Copyright (2014) American Physical Society (APS). This article may be downloaded for personal use only. Any other use requires prior permission of the author and the APS. The following article appeared in Phys. Rev. B 90, 235126 (2014); and may be found at http://journals.aps.org/prb/abstract/10.1103/PhysRevB.90.235126).
@article{photonic5,
title = {One-way absorption of terahertz waves in rod-type and multilayer structures containing polar dielectrics},
author = {Andriy E Serebryannikov and S Nojima and E Ozbay},
url = {http://journals.aps.org/prb/abstract/10.1103/PhysRevB.90.235126},
doi = {10.1103/PhysRevB.90.235126},
year = {2014},
date = {2014-01-01},
journal = {Physical Review B},
volume = {90},
pages = {235126},
abstract = {One-way absorption can be obtained at terahertz frequencies in low-profile rod-type and multilayer dielectric structures with broken spatial inversion symmetry, which contain either a rod layer or an ultrathin homogeneous layer made of a polar dielectric. Perfect absorption for one of the two opposite incidence directions and perfect reflection for the other one are observed at the edge of the polaritonic gap in a wide range of the incident angle variation, when the thickness of the entire structure is of the order of the incident wavelength. Moreover, this regime appears in a wide frequency range, in which the forward-to-backward absorption contrast is strong. The exploited mechanism is connected with the parameter adjustment that enables the location of the polaritonic gap of the polar dielectric, of which the lossy part of the structure is made, inside the stop band arising due to the periodicity of the lossless part of the structure that is made of a nondispersive dielectric. It also exploits absorption enhancement in the lossy part by backing it with the highly reflecting lossless part, which has alternating stop and pass bands.},
note = {Copyright (2014) American Physical Society (APS). This article may be downloaded for personal use only. Any other use requires prior permission of the author and the APS.
The following article appeared in Phys. Rev. B 90, 235126 (2014); and may be found at http://journals.aps.org/prb/abstract/10.1103/PhysRevB.90.235126},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
One-way absorption can be obtained at terahertz frequencies in low-profile rod-type and multilayer dielectric structures with broken spatial inversion symmetry, which contain either a rod layer or an ultrathin homogeneous layer made of a polar dielectric. Perfect absorption for one of the two opposite incidence directions and perfect reflection for the other one are observed at the edge of the polaritonic gap in a wide range of the incident angle variation, when the thickness of the entire structure is of the order of the incident wavelength. Moreover, this regime appears in a wide frequency range, in which the forward-to-backward absorption contrast is strong. The exploited mechanism is connected with the parameter adjustment that enables the location of the polaritonic gap of the polar dielectric, of which the lossy part of the structure is made, inside the stop band arising due to the periodicity of the lossless part of the structure that is made of a nondispersive dielectric. It also exploits absorption enhancement in the lossy part by backing it with the highly reflecting lossless part, which has alternating stop and pass bands.
86.
S Pal, Jarosław W Kłos, K Das, O Hellwig, Paweł Gruszecki, Maciej Krawczyk, A Barman
Optically induced spin wave dynamics in [Co/Pd]8 antidot lattices with perpendicular magnetic anisotropy Journal Article
In: Applied Physics Letters, vol. 105, pp. 162408, 2014, (Copyright (2012) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.).
@article{spinwave_1,
title = {Optically induced spin wave dynamics in [Co/Pd]8 antidot lattices with perpendicular magnetic anisotropy},
author = {S Pal and Jarosław W Kłos and K Das and O Hellwig and Paweł Gruszecki and Maciej Krawczyk and A Barman},
url = {http://scitation.aip.org/content/aip/journal/apl/105/16/10.1063/1.4898774},
doi = {http://dx.doi.org/10.1063/1.4898774},
year = {2014},
date = {2014-01-01},
journal = {Applied Physics Letters},
volume = {105},
pages = {162408},
abstract = {We present an all-optical time-resolved measurement of spin wave (SW) dynamics in a series of antidot lattices based on [Co(0.75 nm)/Pd(0.9 nm)]8 multilayer (ML) systems with perpendicular magnetic anisotropy. The spectra depend significantly on the areal density of the antidots. The observed SW modes are qualitatively reproduced by the plane wave method. The interesting results found in our
measurements and calculations at small lattice constants can be attributed to the increase of areal density of the shells with modified magnetic properties probably due to distortion of the regular ML structure by the Ga ion bombardment and to increased coupling between localized modes. We propose and discuss the possible mechanisms for this coupling including exchange interaction, tunnelling, and dipolar interactions.},
note = {Copyright (2012) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We present an all-optical time-resolved measurement of spin wave (SW) dynamics in a series of antidot lattices based on [Co(0.75 nm)/Pd(0.9 nm)]8 multilayer (ML) systems with perpendicular magnetic anisotropy. The spectra depend significantly on the areal density of the antidots. The observed SW modes are qualitatively reproduced by the plane wave method. The interesting results found in our
measurements and calculations at small lattice constants can be attributed to the increase of areal density of the shells with modified magnetic properties probably due to distortion of the regular ML structure by the Ga ion bombardment and to increased coupling between localized modes. We propose and discuss the possible mechanisms for this coupling including exchange interaction, tunnelling, and dipolar interactions.
measurements and calculations at small lattice constants can be attributed to the increase of areal density of the shells with modified magnetic properties probably due to distortion of the regular ML structure by the Ga ion bombardment and to increased coupling between localized modes. We propose and discuss the possible mechanisms for this coupling including exchange interaction, tunnelling, and dipolar interactions.
85.
Jarosław W Kłos, Maciej Krawczyk, I L Lyubchanskii, N N Dadoenkova, Yu S Dadoenkova
Photonic-magnonic crystals: Multifunctional periodic structures for magnonic and photonic applications Journal Article
In: Journal of Applied Physics, vol. 115, pp. 174311, 2014.
@article{magnonic_photonic,
title = {Photonic-magnonic crystals: Multifunctional periodic structures for magnonic and photonic applications},
author = {Jarosław W Kłos and Maciej Krawczyk and I L Lyubchanskii and N N Dadoenkova and Yu S Dadoenkova},
url = {http://scitation.aip.org/content/aip/journal/jap/115/17/10.1063/1.4874797},
doi = {http://dx.doi.org/10.1063/1.4874797},
year = {2014},
date = {2014-01-01},
journal = {Journal of Applied Physics},
volume = {115},
pages = {174311},
abstract = {We investigate the properties of a photonic-magnonic crystal, a complex multifunctional one-dimensional structure with magnonic and photonic band gaps in the GHz and PHz frequency ranges for spin waves and light, respectively. The system consists of periodically distributed dielectric magnetic slabs of yttrium iron garnet and nonmagnetic spacers with an internal structure of alternating TiO2 and SiO2 layers which form finite-size dielectric photonic crystals. We show that the spin-wave coupling between the magnetic layers, and thus the formation of the magnonic band structure, necessitates a nonzero in-plane component of the spin-wave wave vector. A more complex structure perceived by light is evidenced by the photonic miniband structure and the transmission spectra in which we have observed transmission peaks related to the repetition of the magnetic slabs in the frequency ranges corresponding to the photonic band gaps of the TiO2/SiO2 stack. Moreover, we show that these modes split to very high sharp (a few THz wide) subpeaks in the transmittance spectra. The proposed novel multifunctional artificial crystals can have interesting applications and be used for creating common resonant cavities for spin waves and light to enhance the mutual influence between them.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We investigate the properties of a photonic-magnonic crystal, a complex multifunctional one-dimensional structure with magnonic and photonic band gaps in the GHz and PHz frequency ranges for spin waves and light, respectively. The system consists of periodically distributed dielectric magnetic slabs of yttrium iron garnet and nonmagnetic spacers with an internal structure of alternating TiO2 and SiO2 layers which form finite-size dielectric photonic crystals. We show that the spin-wave coupling between the magnetic layers, and thus the formation of the magnonic band structure, necessitates a nonzero in-plane component of the spin-wave wave vector. A more complex structure perceived by light is evidenced by the photonic miniband structure and the transmission spectra in which we have observed transmission peaks related to the repetition of the magnetic slabs in the frequency ranges corresponding to the photonic band gaps of the TiO2/SiO2 stack. Moreover, we show that these modes split to very high sharp (a few THz wide) subpeaks in the transmittance spectra. The proposed novel multifunctional artificial crystals can have interesting applications and be used for creating common resonant cavities for spin waves and light to enhance the mutual influence between them.
84.
Maciej Krawczyk, D Grundler
Review and prospects of magnonic crystals and devices with reprogrammable band structure Journal Article
In: Journal of Physics: Condensed Matter, vol. 26, pp. 123202, 2014.
@article{magnoniccrystalsb,
title = {Review and prospects of magnonic crystals and devices with reprogrammable band structure},
author = {Maciej Krawczyk and D Grundler},
url = {http://iopscience.iop.org/0953-8984/26/12/123202},
doi = {10.1088/0953-8984/26/12/123202},
year = {2014},
date = {2014-01-01},
journal = {Journal of Physics: Condensed Matter},
volume = {26},
pages = {123202},
abstract = {Research efforts addressing spin waves (magnons) in microand nanostructured ferromagnetic materials have increased tremendously in recent years. Corresponding experimental and theoretical work in magnonics faces significant challenges in that spinwave dispersion relations are highly anisotropic and different magnetic states might be realized via, for example, the magnetic field history. At the same time, these features offer novel opportunities for wave control in solids going beyond photonics and plasmonics. In this topical review we address materials with a periodic modulation of magnetic parameters that give rise to artificially tailored band structures and allow unprecedented control of spin waves. In particular, we discuss recent achievements and perspectives of reconfigurable magnonic devices for which band structures can be reprogrammed during operation. Such characteristics might be useful for multifunctional microwave and logic devices operating over a broad frequency regime on either the macro- or nanoscale.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Research efforts addressing spin waves (magnons) in microand nanostructured ferromagnetic materials have increased tremendously in recent years. Corresponding experimental and theoretical work in magnonics faces significant challenges in that spinwave dispersion relations are highly anisotropic and different magnetic states might be realized via, for example, the magnetic field history. At the same time, these features offer novel opportunities for wave control in solids going beyond photonics and plasmonics. In this topical review we address materials with a periodic modulation of magnetic parameters that give rise to artificially tailored band structures and allow unprecedented control of spin waves. In particular, we discuss recent achievements and perspectives of reconfigurable magnonic devices for which band structures can be reprogrammed during operation. Such characteristics might be useful for multifunctional microwave and logic devices operating over a broad frequency regime on either the macro- or nanoscale.
83.
Jarosław W Kłos, Maciej Krawczyk, Yu S Dadoenkova, N N Dadoenkova, I L Lyubchanskii
Spin Waves and Electromagnetic Waves in Photonic-Magnonic Crystals Journal Article
In: IEEE Transactions on Magnetics, vol. 50, pp. 2504404, 2014, (© 2014 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.).
@article{magnonic_1b,
title = {Spin Waves and Electromagnetic Waves in Photonic-Magnonic Crystals},
author = {Jarosław W Kłos and Maciej Krawczyk and Yu S Dadoenkova and N N Dadoenkova and I L Lyubchanskii},
url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6971774&refinements%3D4270018583%26sortType%3Dasc_p_Sequence%26filter%3DAND%28p_IS_Number%3A6971254%29},
doi = {10.1109/TMAG.2014.2321532},
year = {2014},
date = {2014-01-01},
journal = {IEEE Transactions on Magnetics},
volume = {50},
pages = {2504404},
abstract = {In this paper, we study a periodic 1-D structure with modulated optical and magnetic properties. The considered system represents a photonic-magnonic crystal, in which electromagnetic and spin waves (SWs) can propagate independently encountering bandgaps in the GHz and PHz ranges, respectively. The system consists of periodically arranged dielectric magnetic slabs of yttrium iron garnet and non-magnetic spacers with an internal structure of alternate TiO2 and SiO2 layers, which form finite-size dielectric photonic crystals (PCs). We analyze independently the magnetic and optical properties of these systems in terms of propagation of spin and electromagnetic waves (EMWs). For SWs, we demonstrate that the dynamic dipolar coupling between infinitely extended slabs arranged in a stack depends on the in-plane component of the SWs. For EMWs, the system is a complex magneto-PC with a double periodicity related to the repetition of magnetic slabs and the periodic internal structure of the PC (TiO2/SiO2) layers. This structural complexity has an impact on the electromagnetic spectrum. Minigaps are found within the photonic bands of the infinite TiO2/SiO2 structure, and modes of frequencies within its photonic bandgaps are observed.},
note = {© 2014 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this paper, we study a periodic 1-D structure with modulated optical and magnetic properties. The considered system represents a photonic-magnonic crystal, in which electromagnetic and spin waves (SWs) can propagate independently encountering bandgaps in the GHz and PHz ranges, respectively. The system consists of periodically arranged dielectric magnetic slabs of yttrium iron garnet and non-magnetic spacers with an internal structure of alternate TiO2 and SiO2 layers, which form finite-size dielectric photonic crystals (PCs). We analyze independently the magnetic and optical properties of these systems in terms of propagation of spin and electromagnetic waves (EMWs). For SWs, we demonstrate that the dynamic dipolar coupling between infinitely extended slabs arranged in a stack depends on the in-plane component of the SWs. For EMWs, the system is a complex magneto-PC with a double periodicity related to the repetition of magnetic slabs and the periodic internal structure of the PC (TiO2/SiO2) layers. This structural complexity has an impact on the electromagnetic spectrum. Minigaps are found within the photonic bands of the infinite TiO2/SiO2 structure, and modes of frequencies within its photonic bandgaps are observed.
82.
Andriy E Serebryannikov, P Lalanne, Yu A Petrov, E Ozbay
Wide-angle reflection-mode spatial filtering and splitting with photonic crystal gratings and single-layer rod gratings Journal Article
In: Optics Letters, vol. 39, 2014.
@article{rod_gratings,
title = {Wide-angle reflection-mode spatial filtering and splitting with photonic crystal gratings and single-layer rod gratings},
author = {Andriy E Serebryannikov and P Lalanne and Yu A Petrov and E Ozbay},
doi = {10.1364/OL.39.006193},
year = {2014},
date = {2014-01-01},
journal = {Optics Letters},
volume = {39},
abstract = {New diffractive optical elements offering a frequency tolerant, very efficient, high-pass and bandpass spatial filtering over a broad range of incidence angles are demonstrated by numerical simulations. The device operates in reflection mode owing to the (nearly) perfect blazing. It relies on two-dimensional square-lattice photonic crystals composed of dielectric rods with simple corrugations at the interface. Similar performance can be obtained with gratings composed of a single rod layer placed in the near field of a metal mirror, indicating a route to geometries that can be easily fabricated with modern nanotechnologies. Also equal splitting between zero and first negative orders can be obtained for incidence-angle variations that are wider than 60°.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
New diffractive optical elements offering a frequency tolerant, very efficient, high-pass and bandpass spatial filtering over a broad range of incidence angles are demonstrated by numerical simulations. The device operates in reflection mode owing to the (nearly) perfect blazing. It relies on two-dimensional square-lattice photonic crystals composed of dielectric rods with simple corrugations at the interface. Similar performance can be obtained with gratings composed of a single rod layer placed in the near field of a metal mirror, indicating a route to geometries that can be easily fabricated with modern nanotechnologies. Also equal splitting between zero and first negative orders can be obtained for incidence-angle variations that are wider than 60°.
81.
Aleksandra Trzaskowska, Sławomir Mielcarek, Maciej Wiesner
One-dimensional modulation of the stripe in a surface phononic lattice: The effect on propagation of surface waves Journal Article
In: Journal of Applied Physics, vol. 116, no. 21, 2014, ISSN: 00218979.
@article{Trzaskowska2014,
title = {One-dimensional modulation of the stripe in a surface phononic lattice: The effect on propagation of surface waves},
author = {Aleksandra Trzaskowska and Sławomir Mielcarek and Maciej Wiesner},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84919338541&doi=10.1063%2f1.4902894&partnerID=40&md5=eb6234b8274976b685bba2fd1673f2ab},
doi = {10.1063/1.4902894},
issn = {00218979},
year = {2014},
date = {2014-01-01},
journal = {Journal of Applied Physics},
volume = {116},
number = {21},
publisher = {American Institute of Physics Inc.},
abstract = {Brillouin light scattering was applied for the investigation of surface waves propagation in phononic materials made of a silicon substrate loaded with a permalloy layer and a modulated nanostructure of aluminum stripes. The results revealed the impact of one-dimensional modulation of the surface phononic crystal on the propagation of surface acoustic waves along the modulated aluminum stripes. The dispersion relation was experimentally and theoretically investigated. The new modes propagating in the investigated structure are localized in the stripes and are defined. © 2014 AIP Publishing LLC.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Brillouin light scattering was applied for the investigation of surface waves propagation in phononic materials made of a silicon substrate loaded with a permalloy layer and a modulated nanostructure of aluminum stripes. The results revealed the impact of one-dimensional modulation of the surface phononic crystal on the propagation of surface acoustic waves along the modulated aluminum stripes. The dispersion relation was experimentally and theoretically investigated. The new modes propagating in the investigated structure are localized in the stripes and are defined. © 2014 AIP Publishing LLC.
80.
M Wojtaś, O Czupiński, Zbigniew Tylczyński, D Isakov, M Belsley, R Jakubas
Optical nonlinearity and piezoelectricity in 2,4,6-trimethylpyridinium perchlorate Journal Article
In: Chemical Physics, vol. 441, pp. 59-65, 2014, ISSN: 03010104.
@article{Wojtaś201459,
title = {Optical nonlinearity and piezoelectricity in 2,4,6-trimethylpyridinium perchlorate},
author = {M Wojtaś and O Czupiński and Zbigniew Tylczyński and D Isakov and M Belsley and R Jakubas},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84905233992&doi=10.1016%2fj.chemphys.2014.06.018&partnerID=40&md5=6492e57dcbbc39848380375487908c89},
doi = {10.1016/j.chemphys.2014.06.018},
issn = {03010104},
year = {2014},
date = {2014-01-01},
journal = {Chemical Physics},
volume = {441},
pages = {59-65},
publisher = {Elsevier},
abstract = {[(CH3)3C5H2NH][ClO4] exhibits rich polymorphism, it undergoes four structural phase transitions: from phases I to II at 356/327 K (heating/cooling), II-III at 346/326, III-IV at 226 K and IV-V at 182/170 K. [(CH3)3C5H2NH][ClO4] reveals a strong optical nonlinearity over a wide temperature region with the SHG efficiency comparable to that of KDP. The piezoelectric properties were studied macroscopically by series resonance method over the phases III, IV and V as well as microscopically by means of piezoelectric force microscopy (PFM) in ambient conditions. One of the piezoelectric module at phase transition point at 226 K drops to the value twice smaller than in room temperature what up to now was not encountered in literature. Moreover the ferroelastic phase transition IV-V was observed by means of polarizing optical microscope. The choice of the point group of phase I (Pmmm) was confirmed by the SHG measurements. The updated phase diagram is presented. © 2014 Elsevier Ltd. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
[(CH3)3C5H2NH][ClO4] exhibits rich polymorphism, it undergoes four structural phase transitions: from phases I to II at 356/327 K (heating/cooling), II-III at 346/326, III-IV at 226 K and IV-V at 182/170 K. [(CH3)3C5H2NH][ClO4] reveals a strong optical nonlinearity over a wide temperature region with the SHG efficiency comparable to that of KDP. The piezoelectric properties were studied macroscopically by series resonance method over the phases III, IV and V as well as microscopically by means of piezoelectric force microscopy (PFM) in ambient conditions. One of the piezoelectric module at phase transition point at 226 K drops to the value twice smaller than in room temperature what up to now was not encountered in literature. Moreover the ferroelastic phase transition IV-V was observed by means of polarizing optical microscope. The choice of the point group of phase I (Pmmm) was confirmed by the SHG measurements. The updated phase diagram is presented. © 2014 Elsevier Ltd. All rights reserved.
79.
Zbigniew Tylczyński, Maciej Wiesner
Pyroelectric, piezoelectric, elastic and dielectric properties of triglycine - zinc chloride crystal Journal Article
In: Journal of Alloys and Compounds, vol. 588, pp. 177-181, 2014, ISSN: 09258388.
@article{Tylczyński2014177,
title = {Pyroelectric, piezoelectric, elastic and dielectric properties of triglycine - zinc chloride crystal},
author = {Zbigniew Tylczyński and Maciej Wiesner},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84889671288&doi=10.1016%2fj.jallcom.2013.11.002&partnerID=40&md5=12c518bfab51d16f44b0bc3c35394fa9},
doi = {10.1016/j.jallcom.2013.11.002},
issn = {09258388},
year = {2014},
date = {2014-01-01},
journal = {Journal of Alloys and Compounds},
volume = {588},
pages = {177-181},
abstract = {Temperature changes in the components of pyroelectric, piezoelectric, elastic and dielectric tensors were studied in triglycine zinc chloride crystal in the range 100-300 K. No anomalies in pyroelectric and elastic properties were found. The directions of maximal and minimal values of the elastic susceptibility correspond to the longest and shortest bonds between the Glycine(A)-ZnCl2-Glycine(B) complexes. The attenuations of the resonant vibration along [1 0 0], [0 1 0] and [0 0 1] axes and the corresponding to them d31, d32 and d33 components have maxima at 220 K. The real part of dielectric permittivity ε3′ shows a big jump at 234 K. The imaginary part of all dielectric components have small dispersion above this temperature. Possible phase transition in triglycine zinc chloride crystal has been discussed. © 2013 Elsevier B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Temperature changes in the components of pyroelectric, piezoelectric, elastic and dielectric tensors were studied in triglycine zinc chloride crystal in the range 100-300 K. No anomalies in pyroelectric and elastic properties were found. The directions of maximal and minimal values of the elastic susceptibility correspond to the longest and shortest bonds between the Glycine(A)-ZnCl2-Glycine(B) complexes. The attenuations of the resonant vibration along [1 0 0], [0 1 0] and [0 0 1] axes and the corresponding to them d31, d32 and d33 components have maxima at 220 K. The real part of dielectric permittivity ε3′ shows a big jump at 234 K. The imaginary part of all dielectric components have small dispersion above this temperature. Possible phase transition in triglycine zinc chloride crystal has been discussed. © 2013 Elsevier B.V. All rights reserved.
78.
Zbigniew Tylczyński, P Busz
Transformation from γ to α modification in glycine crystal Journal Article
In: Phase Transitions, vol. 87, no. 10-11, pp. 1157-1164, 2014, ISSN: 01411594.
@article{Tylczyński20141157,
title = {Transformation from γ to α modification in glycine crystal},
author = {Zbigniew Tylczyński and P Busz},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84926200131&doi=10.1080%2f01411594.2014.953951&partnerID=40&md5=57ccd53caa639eb2f6719850f2a51b0f},
doi = {10.1080/01411594.2014.953951},
issn = {01411594},
year = {2014},
date = {2014-01-01},
journal = {Phase Transitions},
volume = {87},
number = {10-11},
pages = {1157-1164},
publisher = {Taylor and Francis Ltd.},
abstract = {In glycine crystal the transformation from γ to α modification has been investigated using differential scanning calorimetry (DSC) and low-frequency dielectric spectroscopy methods on powder and monocrystalline samples. In monocrystalline samples the transition begins at 457.5 K. The first step is connected with cracking of the sample and growing of the ac conductivity which reaches maximum at 458.5 K. Next, ac conductivity achieves a huge maximum at the transition point 462.8 K. Additional small anomaly in the complex dielectric constant was revealed at 335 K. In powder samples this transformation measured by the DSC method goes uniformly. For these samples the ac conductivity begins to grow rapidly from 455 K and grows 2.5 times in the range of 383-387 K. In powder samples the ac conductivity at the transition point is seven times greater than in the monocrystalline samples. Conductivity anomalies are accompanied by changes in the real part of the dielectric constant. © 2014 Taylor & Francis.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In glycine crystal the transformation from γ to α modification has been investigated using differential scanning calorimetry (DSC) and low-frequency dielectric spectroscopy methods on powder and monocrystalline samples. In monocrystalline samples the transition begins at 457.5 K. The first step is connected with cracking of the sample and growing of the ac conductivity which reaches maximum at 458.5 K. Next, ac conductivity achieves a huge maximum at the transition point 462.8 K. Additional small anomaly in the complex dielectric constant was revealed at 335 K. In powder samples this transformation measured by the DSC method goes uniformly. For these samples the ac conductivity begins to grow rapidly from 455 K and grows 2.5 times in the range of 383-387 K. In powder samples the ac conductivity at the transition point is seven times greater than in the monocrystalline samples. Conductivity anomalies are accompanied by changes in the real part of the dielectric constant. © 2014 Taylor & Francis.
77.
B R Srinivasan, T A Naik, Zbigniew Tylczyński, K R Priolkar
Reinvestigation of growth of thiourea urea zinc sulfate crystal Journal Article
In: Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy, vol. 117, pp. 805-809, 2014, ISSN: 13861425.
@article{Srinivasan2014805,
title = {Reinvestigation of growth of thiourea urea zinc sulfate crystal},
author = {B R Srinivasan and T A Naik and Zbigniew Tylczyński and K R Priolkar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84887482944&doi=10.1016%2fj.saa.2013.08.083&partnerID=40&md5=0b7fbe4e8456357349f6b225a8022951},
doi = {10.1016/j.saa.2013.08.083},
issn = {13861425},
year = {2014},
date = {2014-01-01},
journal = {Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy},
volume = {117},
pages = {805-809},
abstract = {Reinvestigation of the growth of thiourea urea zinc sulfate crystal is reported. Aqueous reaction of thiourea, urea and zinc sulfate in 1:1:1 mol ratio results in the formation of the well known [Zn(tu)3(SO4)] (1) (tu = thiourea) crystal and not the 'so called' novel semiorganic nonlinear optical thiourea urea zinc sulfate (2) crystal, as claimed by Redrothu Hanumantha Rao, S. Kalainathan, Spectroscopic investigation, nucleation, growth, optical, thermal and second harmonic studies of novel semi-organic nonlinear optical crystal - Thiourea urea zinc sulfate, Spectrochim. Acta A97 (2012) 456-463. In this work, we demonstrate the usefulness of elemental analytical data, infrared and NMR spectra and X-ray powder pattern, for accurate product characterization. © 2013 Elsevier B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Reinvestigation of the growth of thiourea urea zinc sulfate crystal is reported. Aqueous reaction of thiourea, urea and zinc sulfate in 1:1:1 mol ratio results in the formation of the well known [Zn(tu)3(SO4)] (1) (tu = thiourea) crystal and not the 'so called' novel semiorganic nonlinear optical thiourea urea zinc sulfate (2) crystal, as claimed by Redrothu Hanumantha Rao, S. Kalainathan, Spectroscopic investigation, nucleation, growth, optical, thermal and second harmonic studies of novel semi-organic nonlinear optical crystal - Thiourea urea zinc sulfate, Spectrochim. Acta A97 (2012) 456-463. In this work, we demonstrate the usefulness of elemental analytical data, infrared and NMR spectra and X-ray powder pattern, for accurate product characterization. © 2013 Elsevier B.V. All rights reserved.
76.
Piotr Graczyk, O Maciejewicz, Tomasz Bręczewski, Bogusław Mróz
Temperature dependence of magnetization in nickel thin film sputtered onto ferroelastic gadolinium molybdate substrate Journal Article
In: Ferroelectrics, vol. 465, no. 1, pp. 13-19, 2014, ISSN: 00150193.
@article{Graczyk201413,
title = {Temperature dependence of magnetization in nickel thin film sputtered onto ferroelastic gadolinium molybdate substrate},
author = {Piotr Graczyk and O Maciejewicz and Tomasz Bręczewski and Bogusław Mróz},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84899806397&doi=10.1080%2f10584587.2014.893704&partnerID=40&md5=766d71772e7e62f67d003732effe64a2},
doi = {10.1080/10584587.2014.893704},
issn = {00150193},
year = {2014},
date = {2014-01-01},
journal = {Ferroelectrics},
volume = {465},
number = {1},
pages = {13-19},
publisher = {Taylor and Francis Inc.},
abstract = {The influence of the substrate Gd2(MoO4)3 ferroic phase transition on the magnetization of ferromagnetic nickel thin film was investigated using vibrating sample magnetometer. We have compared experimental results with micromagnetic simulations.Our measurements showed strong magnetization change at Curie Point. We have shown by simulations, taking into consideration magnetoelastic contribution to free energy, that this phenomenon results from the strain-driven spin reorientation transitions. © 2014 Copyright © Taylor & Francis Group, LLC.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The influence of the substrate Gd2(MoO4)3 ferroic phase transition on the magnetization of ferromagnetic nickel thin film was investigated using vibrating sample magnetometer. We have compared experimental results with micromagnetic simulations.Our measurements showed strong magnetization change at Curie Point. We have shown by simulations, taking into consideration magnetoelastic contribution to free energy, that this phenomenon results from the strain-driven spin reorientation transitions. © 2014 Copyright © Taylor & Francis Group, LLC.
75.
Piotr Graczyk, Bogusław Mróz
Simulations of acoustic waves bandgaps in a surface of silicon with a periodic hole structure in a thin nickel film Journal Article
In: AIP Advances, vol. 4, no. 7, 2014, ISSN: 21583226.
@article{Graczyk2014b,
title = {Simulations of acoustic waves bandgaps in a surface of silicon with a periodic hole structure in a thin nickel film},
author = {Piotr Graczyk and Bogusław Mróz},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84905369922&doi=10.1063%2f1.4892076&partnerID=40&md5=510261b40930783d7493645369d93bf8},
doi = {10.1063/1.4892076},
issn = {21583226},
year = {2014},
date = {2014-01-01},
journal = {AIP Advances},
volume = {4},
number = {7},
publisher = {American Institute of Physics Inc.},
abstract = {We have performed simulations of dispersion relations for surface acoustic waves in two-dimensional phononic crystal by the finite elements method (FEM) and by the plane wave method (PWM). Considered medium is a thin nickel layer on a silicon single crystal (001) surface. The nickel film is decorated with cylindrical holes of the depth equal to the nickel film thickness arranged in a square lattice. We have obtained full bandgaps for the surface waves propagating in the medium of particular range of filling factor and layer thickness. The width of the bandgap had reached over 500[MHz] for the sample of the lattice constant 500[nm] and is sufficient for experimental design. © 2014 Author(s).},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We have performed simulations of dispersion relations for surface acoustic waves in two-dimensional phononic crystal by the finite elements method (FEM) and by the plane wave method (PWM). Considered medium is a thin nickel layer on a silicon single crystal (001) surface. The nickel film is decorated with cylindrical holes of the depth equal to the nickel film thickness arranged in a square lattice. We have obtained full bandgaps for the surface waves propagating in the medium of particular range of filling factor and layer thickness. The width of the bandgap had reached over 500[MHz] for the sample of the lattice constant 500[nm] and is sufficient for experimental design. © 2014 Author(s).
74.
Maciej Wiesner, N Lindvall, A Yurgens
Detection of graphene microelectromechanical system resonance Journal Article
In: Journal of Applied Physics, vol. 116, no. 22, 2014, ISSN: 00218979.
@article{Wiesner2014,
title = {Detection of graphene microelectromechanical system resonance},
author = {Maciej Wiesner and N Lindvall and A Yurgens},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84917710953&doi=10.1063%2f1.4903987&partnerID=40&md5=fd2cde2498b271b4b7f9110149493462},
doi = {10.1063/1.4903987},
issn = {00218979},
year = {2014},
date = {2014-01-01},
journal = {Journal of Applied Physics},
volume = {116},
number = {22},
publisher = {American Institute of Physics Inc.},
abstract = {We present an experimental setup for fast detection of resonances of graphene microelectromechanical structures of different quality. The relatively simple technique used to read-out of the resonance frequency is the main advantage of the proposed system. The resolution is good enough to detect vibrations of the graphene resonator with the quality factor of ∼24 and resonance frequency of 104 MHz. © 2014 AIP Publishing LLC.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We present an experimental setup for fast detection of resonances of graphene microelectromechanical structures of different quality. The relatively simple technique used to read-out of the resonance frequency is the main advantage of the proposed system. The resolution is good enough to detect vibrations of the graphene resonator with the quality factor of ∼24 and resonance frequency of 104 MHz. © 2014 AIP Publishing LLC.
2013
73.
V Roboud, Javier Romero Vivas, P Lovera, N Kehagias, T Kehoe, G Redmond, C M Sotomayor Torres
Lasing in nanoimprinted two-dimensional photonic crystal band-edge lasers Journal Article
In: Applied Physics Letters, vol. 102, pp. 073101, 2013, (The following article appeared in Applied Physics Letters Vol.102, Issue 7) and may be found at http://apl.aip.org/resource/1/applab/v102/i7/p073101_s1).
@article{photonicf,
title = {Lasing in nanoimprinted two-dimensional photonic crystal band-edge lasers},
author = {V Roboud and Javier Romero Vivas and P Lovera and N Kehagias and T Kehoe and G Redmond and C M Sotomayor Torres},
url = {http://apl.aip.org/resource/1/applab/v102/i7/p073101_s1},
doi = {10.1063/1.4790646},
year = {2013},
date = {2013-02-01},
journal = {Applied Physics Letters},
volume = {102},
pages = {073101},
abstract = {We demonstrate optically pumped polymer band-edge lasers based on a two-dimensional photonic crystal slab fabricated by nanoimprint lithography (NIL). Lasing was obtained at the photonic band-edge, where the light exhibits a low group velocity at the Γ point of the triangular lattice photonic crystal band structure. The active medium was composed of a dye chromophore-loaded polymer matrix directly patterned in a single step by nanoimprint lithography. Plane-wave and finite difference time domain algorithms were used to predict experimental lasing frequencies and the lasing thresholds obtained at different Γ points. A low laser threshold of 3 μJ/mm2 was achieved in a defect-free photonic crystal thus showing the suitability of nanoimprint lithography to produce cost-efficient optically pumped lasers.},
note = {The following article appeared in Applied Physics Letters Vol.102, Issue 7) and may be found at http://apl.aip.org/resource/1/applab/v102/i7/p073101_s1},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We demonstrate optically pumped polymer band-edge lasers based on a two-dimensional photonic crystal slab fabricated by nanoimprint lithography (NIL). Lasing was obtained at the photonic band-edge, where the light exhibits a low group velocity at the Γ point of the triangular lattice photonic crystal band structure. The active medium was composed of a dye chromophore-loaded polymer matrix directly patterned in a single step by nanoimprint lithography. Plane-wave and finite difference time domain algorithms were used to predict experimental lasing frequencies and the lasing thresholds obtained at different Γ points. A low laser threshold of 3 μJ/mm2 was achieved in a defect-free photonic crystal thus showing the suitability of nanoimprint lithography to produce cost-efficient optically pumped lasers.
72.
Jarosław W Kłos, D Kumar, Maciej Krawczyk, A Barman
Magnonic band engineering by intrinsic and extrinsic mirror symmetry breaking in antidot spin-wave waveguides Journal Article
In: Scientific Reports, vol. 3, pp. 2444, 2013, (Copyright © 2013, Rights Managed by Nature Publishing Group).
@article{spinwaveb,
title = {Magnonic band engineering by intrinsic and extrinsic mirror symmetry breaking in antidot spin-wave waveguides},
author = {Jarosław W Kłos and D Kumar and Maciej Krawczyk and A Barman},
url = {http://www.nature.com/srep/2013/130815/srep02444/full/srep02444.html},
doi = {10.1038/srep02444},
year = {2013},
date = {2013-01-01},
journal = {Scientific Reports},
volume = {3},
pages = {2444},
abstract = {We theoretically study the spin-wave spectra in magnonic waveguides periodically patterned with nanoscale square antidots. We show that structural changes breaking the mirror symmetry of the waveguide can close the magnonic bandgap. The effect of these intrinsic symmetry breaking can be compensated by adjusted asymmetric external bias magnetic field, i.e., by an extrinsic factor. This allows for the recovery of the magnonic bandgaps. The described methods can be used for developing parallel models for recovering bandgaps closed due to a fabrication defect. The model developed here is particular to magnonics, an emerging field combining spin dynamics and spintronics. However, the underlying principle of this development is squarely based upon the translational and mirror symmetries, thus, we believe that this idea of correcting an intrinsic defect by extrinsic means, should be applicable to spin-waves in both exchange and dipolar interaction regimes, as well as to other waves in general.},
note = {Copyright © 2013, Rights Managed by Nature Publishing Group},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We theoretically study the spin-wave spectra in magnonic waveguides periodically patterned with nanoscale square antidots. We show that structural changes breaking the mirror symmetry of the waveguide can close the magnonic bandgap. The effect of these intrinsic symmetry breaking can be compensated by adjusted asymmetric external bias magnetic field, i.e., by an extrinsic factor. This allows for the recovery of the magnonic bandgaps. The described methods can be used for developing parallel models for recovering bandgaps closed due to a fabrication defect. The model developed here is particular to magnonics, an emerging field combining spin dynamics and spintronics. However, the underlying principle of this development is squarely based upon the translational and mirror symmetries, thus, we believe that this idea of correcting an intrinsic defect by extrinsic means, should be applicable to spin-waves in both exchange and dipolar interaction regimes, as well as to other waves in general.
71.
Maciej Krawczyk, Sławomir Mamica, Michał Mruczkiewicz, Jarosław W Kłos, S Tacchi, M Madami, G Gubbiotti, G Duerr, D Grundler
Magnonic band structures in two-dimensional bi-component magnonic crystals with in-plane magnetization Journal Article
In: Journal of Physics D: Applied Physics, vol. 46, pp. 495003, 2013.
@article{SW_1,
title = {Magnonic band structures in two-dimensional bi-component magnonic crystals with in-plane magnetization},
author = {Maciej Krawczyk and Sławomir Mamica and Michał Mruczkiewicz and Jarosław W Kłos and S Tacchi and M Madami and G Gubbiotti and G Duerr and D Grundler},
url = {http://stacks.iop.org/JPhysD/46/495003},
doi = {10.1088/0022-3727/46/49/495003},
year = {2013},
date = {2013-01-01},
journal = {Journal of Physics D: Applied Physics},
volume = {46},
pages = {495003},
abstract = {We investigate the magnonic band structure of in-plane magnetized two-dimensional magnonic crystals composed of cobalt dots embedded into a permalloy antidot lattice. Our analysis is based on the results of numerical calculations carried out by the plane wave method. The complex magnonic band structure found in square-lattice magnonic crystals is explained on the basis of the spin wave dispersion relations calculated in the empty lattice model. We show that four principal effects influence the formation of a magnonic band structure in planar two-dimensional bi-component magnonic crystals: a folding effect, Bragg scattering, hybridization between various spin wave modes, and a demagnetizing field. While the first two effects are found for other types of waves in periodic composites, the third one
exists in an anisotropic medium and the last one is specific to spin waves propagating in magnonic crystals with magnetization in the film plane. The strong anisotropy in the dispersion relation of spin waves in thin ferromagnetic films results in the crossing and anti-crossing of the fast, Damon–Eshbach-like mode with a number of other spin waves folded to the first Brillouin zone. The demagnetizing field can induce the formation of channels for spin waves which are propagating perpendicular to the external magnetic field direction, but this property exists only in the limiting range of the thicknesses and the lattice constants of the bi-component magnonic crystals. Based on the model analysis we propose a modification of the magnonic crystal structure by changing its thickness, lattice constant and aspect ratio along the direction of the applied magnetic field to significantly modify the magnonic band structure and obtain partial magnonic band gaps.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We investigate the magnonic band structure of in-plane magnetized two-dimensional magnonic crystals composed of cobalt dots embedded into a permalloy antidot lattice. Our analysis is based on the results of numerical calculations carried out by the plane wave method. The complex magnonic band structure found in square-lattice magnonic crystals is explained on the basis of the spin wave dispersion relations calculated in the empty lattice model. We show that four principal effects influence the formation of a magnonic band structure in planar two-dimensional bi-component magnonic crystals: a folding effect, Bragg scattering, hybridization between various spin wave modes, and a demagnetizing field. While the first two effects are found for other types of waves in periodic composites, the third one
exists in an anisotropic medium and the last one is specific to spin waves propagating in magnonic crystals with magnetization in the film plane. The strong anisotropy in the dispersion relation of spin waves in thin ferromagnetic films results in the crossing and anti-crossing of the fast, Damon–Eshbach-like mode with a number of other spin waves folded to the first Brillouin zone. The demagnetizing field can induce the formation of channels for spin waves which are propagating perpendicular to the external magnetic field direction, but this property exists only in the limiting range of the thicknesses and the lattice constants of the bi-component magnonic crystals. Based on the model analysis we propose a modification of the magnonic crystal structure by changing its thickness, lattice constant and aspect ratio along the direction of the applied magnetic field to significantly modify the magnonic band structure and obtain partial magnonic band gaps.
exists in an anisotropic medium and the last one is specific to spin waves propagating in magnonic crystals with magnetization in the film plane. The strong anisotropy in the dispersion relation of spin waves in thin ferromagnetic films results in the crossing and anti-crossing of the fast, Damon–Eshbach-like mode with a number of other spin waves folded to the first Brillouin zone. The demagnetizing field can induce the formation of channels for spin waves which are propagating perpendicular to the external magnetic field direction, but this property exists only in the limiting range of the thicknesses and the lattice constants of the bi-component magnonic crystals. Based on the model analysis we propose a modification of the magnonic crystal structure by changing its thickness, lattice constant and aspect ratio along the direction of the applied magnetic field to significantly modify the magnonic band structure and obtain partial magnonic band gaps.
70.
Michał Mruczkiewicz, Maciej Krawczyk, G Gubbiotti, S Tacchi, Yu A Filimonov, D V Kalyabin, I V Lisenkov, S A Nikitov
Nonreciprocity of spin waves in metallized Journal Article
In: New Journal of Physics, vol. 15, pp. 113023, 2013.
@article{magnonicsc,
title = {Nonreciprocity of spin waves in metallized},
author = {Michał Mruczkiewicz and Maciej Krawczyk and G Gubbiotti and S Tacchi and Yu A Filimonov and D V Kalyabin and I V Lisenkov and S A Nikitov},
url = {http://stacks.iop.org/1367-2630/15/113023},
doi = {10.1088/1367-2630/15/11/113023},
year = {2013},
date = {2013-01-01},
journal = {New Journal of Physics},
volume = {15},
pages = {113023},
abstract = {The nonreciprocal properties of spin waves in metallized onedimensional bi-component magnonic crystal composed of two materials with different magnetizations are investigated numerically. nonreciprocity leads to the appearance of indirect magnonic band gaps for magnonic crystals with both low and high magnetization contrast. Specific features of the nonreciprocity in low contrast magnonic crystals lead to the appearance of several magnonic band gaps located within the first Brillouin zone for waves propagating along the metallized surface. Analysis of the spatial distribution of dynamic magnetization amplitudes explains the mechanism of dispersion band formation and hybridization between magnonic bands in magnonic crystals with metallization.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The nonreciprocal properties of spin waves in metallized onedimensional bi-component magnonic crystal composed of two materials with different magnetizations are investigated numerically. nonreciprocity leads to the appearance of indirect magnonic band gaps for magnonic crystals with both low and high magnetization contrast. Specific features of the nonreciprocity in low contrast magnonic crystals lead to the appearance of several magnonic band gaps located within the first Brillouin zone for waves propagating along the metallized surface. Analysis of the spatial distribution of dynamic magnetization amplitudes explains the mechanism of dispersion band formation and hybridization between magnonic bands in magnonic crystals with metallization.
69.
G Scherrer, M Hofman, Wojciech Śmigaj, M Kadic, T-M Chang, X Mélique, D Lippens, O Vanbésien, B Cluzel, F Fornel, S Guenneau, B Gralak
Photonic crystal carpet: Manipulating wave fronts in the near field at 1.55 μm_1 Journal Article
In: Physical Review B, vol. 88, pp. 1151, 2013, (Copyright (2013) by the American Physical Society. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.).
@article{photonic_1b,
title = {Photonic crystal carpet: Manipulating wave fronts in the near field at 1.55 μm_1},
author = {G Scherrer and M Hofman and Wojciech Śmigaj and M Kadic and T-M Chang and X Mélique and D Lippens and O Vanbésien and B Cluzel and F Fornel and S Guenneau and B Gralak},
url = {http://prb.aps.org/abstract/PRB/v88/i11/e115110},
doi = {10.1103/PhysRevB.88.115110},
year = {2013},
date = {2013-01-01},
journal = {Physical Review B},
volume = {88},
pages = {1151},
abstract = {Ground-plane cloaks, which transform a curved mirror into a flat one, and recently reported at wavelengths ranging from the optical to the visible spectrum, bring the realm of optical illusion a step closer to reality. However, all carpet-cloaking experiments have thus far been carried out in the far field. Here, we demonstrate numerically and experimentally that a dielectric photonic crystal (PC) of an irregular shape made of a honeycomb array of air holes can scatter waves in the near field like a PC with a flat boundary at stop band frequencies. This mirage effect relies upon a specific arrangement of dielectric pillars placed at the nodes of a quasiconformal grid dressing the PC. Our carpet is experimentally shown to flatten the scattered wave fronts of a PC with a bump throughout the range of wavelengths from 1520 to 1580 nm within the stop band extending from 1280 to 1940 nm. The device has been fabricated using a single-mask advanced nanoelectronics technique on III-V semiconductors and the near field measurements have been carried out in order to image the wave fronts’ curvatures around the telecommunication wavelength 1550 nm. Interestingly, comparisons of our near-field experimental results with full-wave simulations suggest the relatively low aspect ratio of the fabricated carpet (pillars have 200 nm diameter and 2 μm height) makes it inherently three dimensional. Moreover, this carpet is constrained to normal incidence. We therefore propose an elaborated design of the carpet (with pillars of varying radii) which should work at different angles of incidence.},
note = {Copyright (2013) by the American Physical
Society. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Ground-plane cloaks, which transform a curved mirror into a flat one, and recently reported at wavelengths ranging from the optical to the visible spectrum, bring the realm of optical illusion a step closer to reality. However, all carpet-cloaking experiments have thus far been carried out in the far field. Here, we demonstrate numerically and experimentally that a dielectric photonic crystal (PC) of an irregular shape made of a honeycomb array of air holes can scatter waves in the near field like a PC with a flat boundary at stop band frequencies. This mirage effect relies upon a specific arrangement of dielectric pillars placed at the nodes of a quasiconformal grid dressing the PC. Our carpet is experimentally shown to flatten the scattered wave fronts of a PC with a bump throughout the range of wavelengths from 1520 to 1580 nm within the stop band extending from 1280 to 1940 nm. The device has been fabricated using a single-mask advanced nanoelectronics technique on III-V semiconductors and the near field measurements have been carried out in order to image the wave fronts’ curvatures around the telecommunication wavelength 1550 nm. Interestingly, comparisons of our near-field experimental results with full-wave simulations suggest the relatively low aspect ratio of the fabricated carpet (pillars have 200 nm diameter and 2 μm height) makes it inherently three dimensional. Moreover, this carpet is constrained to normal incidence. We therefore propose an elaborated design of the carpet (with pillars of varying radii) which should work at different angles of incidence.
68.
G Venkat, D Kumar, M Franchin, O Dmytriiev, Michał Mruczkiewicz, H Fangohr, A Barman, Maciej Krawczyk, A Prabhakar
Proposal for a standard micromagnetic problem: Spin wave dispersion in a magnonic waveguide Journal Article
In: IEEE Transactions on Magnetics, vol. 49, no. 1, pp. 524, 2013, (Copyright IEEE Trans. Magn. 2013).
@article{23,
title = {Proposal for a standard micromagnetic problem: Spin wave dispersion in a magnonic waveguide},
author = {G Venkat and D Kumar and M Franchin and O Dmytriiev and Michał Mruczkiewicz and H Fangohr and A Barman and Maciej Krawczyk and A Prabhakar},
url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?reload=true&arnumber=6228538},
doi = {10.1109/TMAG.2012.2206820},
year = {2013},
date = {2013-01-01},
journal = {IEEE Transactions on Magnetics},
volume = {49},
number = {1},
pages = {524},
abstract = {In this paper, we propose a standard micromagnetic problem, of a nanostripe of permalloy. We study the magnetization dynamics and describe methods of extracting features from simulations. Spin wave dispersion curves, relating frequency and wave vector, are obtained for wave propagation in different directions relativeto the axis of the waveguide and the external appliedfield. Simulation results using bothfinite element (Nmag) andfinite difference (OOMMF) methods are compared against analytic results, for different ranges of the
wave vector.},
note = {Copyright IEEE Trans. Magn. 2013},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this paper, we propose a standard micromagnetic problem, of a nanostripe of permalloy. We study the magnetization dynamics and describe methods of extracting features from simulations. Spin wave dispersion curves, relating frequency and wave vector, are obtained for wave propagation in different directions relativeto the axis of the waveguide and the external appliedfield. Simulation results using bothfinite element (Nmag) andfinite difference (OOMMF) methods are compared against analytic results, for different ranges of the
wave vector.
wave vector.
67.
R Huber, Maciej Krawczyk, T Schwarze, H Yu, G Duerr, S Albert, D Grundler
Reciprocal Damon-Eshbach-type spin wave excitation in a magnonic crystal due to tunable magnetic symmetry Journal Article
In: Applied Physics Letters, vol. 102, pp. 012403, 2013, (The following article appeared in Applied Physics Letters Vol.101, Issue 4) and may be found at http://link.aip.org/link/?APL/101/042404).
@article{swb,
title = {Reciprocal Damon-Eshbach-type spin wave excitation in a magnonic crystal due to tunable magnetic symmetry},
author = {R Huber and Maciej Krawczyk and T Schwarze and H Yu and G Duerr and S Albert and D Grundler},
url = {http://apl.aip.org/resource/1/applab/v102/i1/p012403_s1},
doi = {10.1063/1.4773522},
year = {2013},
date = {2013-01-01},
journal = {Applied Physics Letters},
volume = {102},
pages = {012403},
abstract = {We report spin-wave (SW) propagation in a one-dimensional magnonic crystal (MC) explored by all electrical spectroscopy. The MC consists of a periodic array of 255 nm wide permalloy nanowires with a small edge-to-edge separation of 45 nm. Provoking antiparallel alignment of the magnetization of neighboring nanowires, we unexpectedly find reciprocal excitation of Damon-Eshbach type SWs. The characteristics are in contrast to ferromagnetic thin films and controlled via, both, the external magnetic field and magnetic states. The observed reciprocal excitation is a metamaterial property for SWs and attributed to the peculiar magnetic symmetry of the artificially tailored magnetic material. The findings offer great perspectives for nanoscale SW interference devices.},
note = {The following article appeared in Applied Physics Letters Vol.101, Issue 4) and may be found at http://link.aip.org/link/?APL/101/042404},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We report spin-wave (SW) propagation in a one-dimensional magnonic crystal (MC) explored by all electrical spectroscopy. The MC consists of a periodic array of 255 nm wide permalloy nanowires with a small edge-to-edge separation of 45 nm. Provoking antiparallel alignment of the magnetization of neighboring nanowires, we unexpectedly find reciprocal excitation of Damon-Eshbach type SWs. The characteristics are in contrast to ferromagnetic thin films and controlled via, both, the external magnetic field and magnetic states. The observed reciprocal excitation is a metamaterial property for SWs and attributed to the peculiar magnetic symmetry of the artificially tailored magnetic material. The findings offer great perspectives for nanoscale SW interference devices.
66.
M Madami, S Tacchi, G Gubbiotti, G Carlotti, J Ding, A O Adeyeye, Jarosław W Kłos, Maciej Krawczyk
Spin wave dispersion in permalloy antidot array with alternating holes diameter Journal Article
In: IEEE Transactions on Magnetics, vol. 49, no. 7, pp. 3093, 2013.
@article{magnonich,
title = {Spin wave dispersion in permalloy antidot array with alternating holes diameter},
author = {M Madami and S Tacchi and G Gubbiotti and G Carlotti and J Ding and A O Adeyeye and Jarosław W Kłos and Maciej Krawczyk},
url = {http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=6559179&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D6559179},
doi = {10.1109/TMAG.2013.2240659},
year = {2013},
date = {2013-01-01},
journal = {IEEE Transactions on Magnetics},
volume = {49},
number = {7},
pages = {3093},
abstract = {The dispersion of spin waves in a Permalloy binary antidot array constituted by two alternated antidot sublattices with different diameters of the circular holes has been investigated. The diameters of the holes are 300 nm and 150 nm with a holes center-to-center spacing of 425 nm. The spin wave frequency has been measured with Brillouin light scattering applying a magnetic field along the edge of the square unit cell of the lattice and sweeping the spin-wave wave vector along the perpendicular direction. The measured dispersion has been compared with calculations performed by the plane wave method, achieving a good agreement with the experimental results over the whole wave vector range.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The dispersion of spin waves in a Permalloy binary antidot array constituted by two alternated antidot sublattices with different diameters of the circular holes has been investigated. The diameters of the holes are 300 nm and 150 nm with a holes center-to-center spacing of 425 nm. The spin wave frequency has been measured with Brillouin light scattering applying a magnetic field along the edge of the square unit cell of the lattice and sweeping the spin-wave wave vector along the perpendicular direction. The measured dispersion has been compared with calculations performed by the plane wave method, achieving a good agreement with the experimental results over the whole wave vector range.
65.
Sławomir Mamica
Spin-wave spectra and stability of the in-plane vortex state in two-dimensional magnetic nanorings Journal Article
In: Journal of Applied Physics, vol. 114, pp. 233906, 2013.
@article{SM2013JAP3,
title = {Spin-wave spectra and stability of the in-plane vortex state in two-dimensional magnetic nanorings},
author = {Sławomir Mamica},
url = {http://scitation.aip.org/content/aip/journal/jap/114/23/10.1063/1.4851695},
doi = {10.1063/1.4851695},
year = {2013},
date = {2013-01-01},
journal = {Journal of Applied Physics},
volume = {114},
pages = {233906},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
64.
Sławomir Mamica
Stabilization of the in-plane vortex state in two-dimensional circular nanorings Journal Article
In: Journal of Applied Physics, vol. 113, pp. 093901, 2013.
@article{Mamica2013a,
title = {Stabilization of the in-plane vortex state in two-dimensional circular nanorings},
author = {Sławomir Mamica},
year = {2013},
date = {2013-01-01},
journal = {Journal of Applied Physics},
volume = {113},
pages = {093901},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
63.
Michał Mruczkiewicz, Maciej Krawczyk, V K Skaharov, Yu V Khivintsev, Yu A Filimonov, S A Nikitov
Standing spin waves in magnonic crystals Journal Article
In: Journal of Applied Physics, vol. 113, no. 9, pp. 093908, 2013, (The following article appeared in Journl of Applied Physics Vol.113, Issue 9) and may be found at http://jap.aip.org/resource/1/japiau/v113/i9/p093908_s1).
@article{mcg,
title = {Standing spin waves in magnonic crystals},
author = {Michał Mruczkiewicz and Maciej Krawczyk and V K Skaharov and Yu V Khivintsev and Yu A Filimonov and S A Nikitov},
url = {http://jap.aip.org/resource/1/japiau/v113/i9/p093908_s1},
doi = {10.1063/1.4793085},
year = {2013},
date = {2013-01-01},
journal = {Journal of Applied Physics},
volume = {113},
number = {9},
pages = {093908},
abstract = {The features of standing spin waves (SWs) excited during ferromagnetic resonance in three different one-dimensional magnonic crystals (MC) are intensively studied. The investigated magnonic crystals were: an array of air-spaced cobalt stripes, an array of air-spaced permalloy (Py) stripes, and a bi-component MC composed of alternating Co and Py stripes. All MC structures were made by etching technique from Co and Py thin films deposited onto Si substrates. Two configurations are considered with the in-plane external magnetic field applied parallel or perpendicular to the stripes. The supporting calculations are performed by the finite element method in the frequency domain. A number of intensive SW modes occurred in periodic structures under ferromagnetic resonance conditions as a consequence of standing spin waves excitation. These modes were analyzed theoretically in order to explain the origins of SW excitations. With the support of numerical calculations, we analyze also the possible scenarios for the occurrence of standing SWs in the investigated structures. It is demonstrated that the SW propagation length is an important factor conditioning the standing SW formation in MCs.},
note = {The following article appeared in Journl of Applied Physics Vol.113, Issue 9) and may be found at http://jap.aip.org/resource/1/japiau/v113/i9/p093908_s1},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The features of standing spin waves (SWs) excited during ferromagnetic resonance in three different one-dimensional magnonic crystals (MC) are intensively studied. The investigated magnonic crystals were: an array of air-spaced cobalt stripes, an array of air-spaced permalloy (Py) stripes, and a bi-component MC composed of alternating Co and Py stripes. All MC structures were made by etching technique from Co and Py thin films deposited onto Si substrates. Two configurations are considered with the in-plane external magnetic field applied parallel or perpendicular to the stripes. The supporting calculations are performed by the finite element method in the frequency domain. A number of intensive SW modes occurred in periodic structures under ferromagnetic resonance conditions as a consequence of standing spin waves excitation. These modes were analyzed theoretically in order to explain the origins of SW excitations. With the support of numerical calculations, we analyze also the possible scenarios for the occurrence of standing SWs in the investigated structures. It is demonstrated that the SW propagation length is an important factor conditioning the standing SW formation in MCs.
62.
Jarosław W Kłos, V S Tkachenko
Symmetry-related criteria for the occurrence of defect states in magnonic superlattices Journal Article
In: Journal of Applied Physics, vol. 113, pp. 133907, 2013.
@article{c_73,
title = {Symmetry-related criteria for the occurrence of defect states in magnonic superlattices},
author = {Jarosław W Kłos and V S Tkachenko},
url = {http://jap.aip.org/resource/1/japiau/v113/i13/p133907_s1},
doi = {10.1063/1.4798607},
year = {2013},
date = {2013-01-01},
journal = {Journal of Applied Physics},
volume = {113},
pages = {133907},
abstract = {We investigate analytically the occurrence of magnonic defect states in the exchange regime for the system geometry with the defect linking two semi-infinite superlattices at the same symmetry points. The frequency ranges forbidden and allowed to defect states are determined in the low-frequency region. Non-overlapping frequency ranges allowed to either even or odd defect states are found to occur within each forbidden gap in higher frequencies. Our semi-analytical calculations of the dispersion relation based on the solutions obtained in the matching procedure are supported by the computed transmission spectra.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We investigate analytically the occurrence of magnonic defect states in the exchange regime for the system geometry with the defect linking two semi-infinite superlattices at the same symmetry points. The frequency ranges forbidden and allowed to defect states are determined in the low-frequency region. Non-overlapping frequency ranges allowed to either even or odd defect states are found to occur within each forbidden gap in higher frequencies. Our semi-analytical calculations of the dispersion relation based on the solutions obtained in the matching procedure are supported by the computed transmission spectra.
61.
Sławomir Mamica
Tailoring of the partial magnonic gap in three-dimensional magnetoferritin-based magnonic crystals Journal Article
In: Journal of Applied Physics, vol. 114, pp. 043912, 2013.
@article{Mamica2013b,
title = {Tailoring of the partial magnonic gap in three-dimensional magnetoferritin-based magnonic crystals},
author = {Sławomir Mamica},
url = {http://scitation.aip.org/content/aip/journal/jap/114/4/10.1063/1.4816684?ver=pdfcov},
doi = {10.1063/1.4816684},
year = {2013},
date = {2013-01-01},
journal = {Journal of Applied Physics},
volume = {114},
pages = {043912},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
60.
P Depondt, J-C S Lévy, Sławomir Mamica
Vortex polarization dynamics in a square magnetic nanodot Journal Article
In: Journal of Physics: Condensed Matter, vol. 25, pp. 466001, 2013.
@article{PhD2013,
title = {Vortex polarization dynamics in a square magnetic nanodot},
author = {P Depondt and J-C S Lévy and Sławomir Mamica},
url = {http://iopscience.iop.org/0953-8984/25/46/466001/},
doi = {10.1088/0953-8984/25/46/466001},
year = {2013},
date = {2013-01-01},
journal = {Journal of Physics: Condensed Matter},
volume = {25},
pages = {466001},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
59.
Aleksandra Trzaskowska, Sławomir Mielcarek, J Sarkar
Band gap in hypersonic surface phononic lattice of nickel pillars Journal Article
In: Journal of Applied Physics, vol. 114, no. 13, 2013, ISSN: 00218979.
@article{Trzaskowska2013,
title = {Band gap in hypersonic surface phononic lattice of nickel pillars},
author = {Aleksandra Trzaskowska and Sławomir Mielcarek and J Sarkar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84885446112&doi=10.1063%2f1.4824103&partnerID=40&md5=39cb248d574115a0dff7be6e7fda757f},
doi = {10.1063/1.4824103},
issn = {00218979},
year = {2013},
date = {2013-01-01},
journal = {Journal of Applied Physics},
volume = {114},
number = {13},
abstract = {Brillouin light scattering was applied for investigation of surface wave propagation in phononic materials made of a silicon surface loaded with a nanostructure of nickel pillars. The results revealed the presence of phononic energy gap in the GHz range. The presence of such an energy gap was theoretically confirmed by the finite element method. The width of the energy gap was found to be related to the height of the pillars and was shown to be limited by the frequencies of the modes localized in the pillars. The modes were thoroughly analysed. © 2013 AIP Publishing LLC.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Brillouin light scattering was applied for investigation of surface wave propagation in phononic materials made of a silicon surface loaded with a nanostructure of nickel pillars. The results revealed the presence of phononic energy gap in the GHz range. The presence of such an energy gap was theoretically confirmed by the finite element method. The width of the energy gap was found to be related to the height of the pillars and was shown to be limited by the frequencies of the modes localized in the pillars. The modes were thoroughly analysed. © 2013 AIP Publishing LLC.
58.
Bartosz Graczykowski, Sławomir Mielcarek, Tomasz Bręczewski, M L No, J San Juan, Bogusław Mróz
Martensitic phase transition in Cu-14%Al-4%Ni shape memory alloys studied by Brillouin light scattering Journal Article
In: Smart Materials and Structures, vol. 22, no. 8, 2013, ISSN: 09641726.
@article{Graczykowski2013,
title = {Martensitic phase transition in Cu-14%Al-4%Ni shape memory alloys studied by Brillouin light scattering},
author = {Bartosz Graczykowski and Sławomir Mielcarek and Tomasz Bręczewski and M L No and J San Juan and Bogusław Mróz},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84881177216&doi=10.1088%2f0964-1726%2f22%2f8%2f085027&partnerID=40&md5=12e29b9e8f5f56d7777e8007f867c27c},
doi = {10.1088/0964-1726/22/8/085027},
issn = {09641726},
year = {2013},
date = {2013-01-01},
journal = {Smart Materials and Structures},
volume = {22},
number = {8},
abstract = {The paper presents the influence of the martensitic phase transition on hypersonic thermally excited surface acoustic waves propagating in Cu-14%Al-4%Ni (wt%) shape memory alloy. Non-destructive and non-contact testing using Brillouin light scattering spectroscopy permitted determination of the elastic constants of austenite versus temperature. Experimental results obtained for martensite were interpreted using the proposed model of the cubic to orthorhombic martensitic phase transition based on the Landau model of a first-order phase transition. Additionally we adopted the approximation of the domain structure of martensite by a polycrystalline sample using the Voigt-Reuss-Hill procedure of averaging the elastic constants. © 2013 IOP Publishing Ltd.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The paper presents the influence of the martensitic phase transition on hypersonic thermally excited surface acoustic waves propagating in Cu-14%Al-4%Ni (wt%) shape memory alloy. Non-destructive and non-contact testing using Brillouin light scattering spectroscopy permitted determination of the elastic constants of austenite versus temperature. Experimental results obtained for martensite were interpreted using the proposed model of the cubic to orthorhombic martensitic phase transition based on the Landau model of a first-order phase transition. Additionally we adopted the approximation of the domain structure of martensite by a polycrystalline sample using the Voigt-Reuss-Hill procedure of averaging the elastic constants. © 2013 IOP Publishing Ltd.
57.
H Małuszyńska, Zbigniew Tylczyński, A Cousson
Ferroelastoelectric ordering in (NH4)2CuBr 4·2H2O single crystal Journal Article
In: CrystEngComm, vol. 15, no. 37, pp. 7498-7504, 2013, ISSN: 14668033.
@article{Małuszyńska20137498,
title = {Ferroelastoelectric ordering in (NH4)2CuBr 4·2H2O single crystal},
author = {H Małuszyńska and Zbigniew Tylczyński and A Cousson},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84883726044&doi=10.1039%2fc3ce41113c&partnerID=40&md5=d21b8382d4044ad3d4c9f4729d3e5d2e},
doi = {10.1039/c3ce41113c},
issn = {14668033},
year = {2013},
date = {2013-01-01},
journal = {CrystEngComm},
volume = {15},
number = {37},
pages = {7498-7504},
abstract = {The diammonium tetrabromocuprate dihydrate single crystal, (NH 4)2CuBr4·2H2O, was studied by six different techniques: single-crystal X-ray and neutron diffraction, differential scanning calorimetry, dielectric permittivity, conoscopic figures and piezoelectric resonances. The compound undergoes a weak second order phase transition at 158 K changing the symmetry from P42/mnm to P42 1m. The piezoelectric effect observed below 158 K confirmed the non-centrosymmetric low-temperature crystal phase. The X-ray diffraction studies performed at 296 and 120 K and the single neutron diffraction studies at 293 and 20 K determined structures of both phases with high precision. Only neutron results allowed to describe the mechanism of the phase transition, which is entirely connected with the orientational ordering of hydrogen atoms from ammonium groups. The phase transition is classified as an order-disorder continuous one. The low-temperature phase has a ferroelastoelectric higher-order ferroic ordering and the piezoelectric tensor is the macroscopic order parameter. © 2013 The Royal Society of Chemistry.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The diammonium tetrabromocuprate dihydrate single crystal, (NH 4)2CuBr4·2H2O, was studied by six different techniques: single-crystal X-ray and neutron diffraction, differential scanning calorimetry, dielectric permittivity, conoscopic figures and piezoelectric resonances. The compound undergoes a weak second order phase transition at 158 K changing the symmetry from P42/mnm to P42 1m. The piezoelectric effect observed below 158 K confirmed the non-centrosymmetric low-temperature crystal phase. The X-ray diffraction studies performed at 296 and 120 K and the single neutron diffraction studies at 293 and 20 K determined structures of both phases with high precision. Only neutron results allowed to describe the mechanism of the phase transition, which is entirely connected with the orientational ordering of hydrogen atoms from ammonium groups. The phase transition is classified as an order-disorder continuous one. The low-temperature phase has a ferroelastoelectric higher-order ferroic ordering and the piezoelectric tensor is the macroscopic order parameter. © 2013 The Royal Society of Chemistry.
56.
Zbigniew Tylczyński, Aleksandra Trzaskowska
Elastic and elasto-optical properties of triglycine-zinc chloride crystal Journal Article
In: Journal of Applied Physics, vol. 114, no. 3, 2013, ISSN: 00218979.
@article{Tylczyński2013,
title = {Elastic and elasto-optical properties of triglycine-zinc chloride crystal},
author = {Zbigniew Tylczyński and Aleksandra Trzaskowska},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84880848583&doi=10.1063%2f1.4816048&partnerID=40&md5=d07db8624dc1ae93fdca87e2b2601846},
doi = {10.1063/1.4816048},
issn = {00218979},
year = {2013},
date = {2013-01-01},
journal = {Journal of Applied Physics},
volume = {114},
number = {3},
abstract = {The behaviours of bulk phonons propagating in triglycine-zinc chloride (Gly3-ZnCl2) single crystal for different polarizations of the incident and scattered beams were studied by Brillouin spectroscopy. All components of the elastic and elasto-optical tensors were determined at room temperature. Dependences of the velocities of quasi-longitudinal, transverse, and quasi-transverse phonons propagating in the planes (110), (101), and (011) on the direction of propagation are presented. © 2013 AIP Publishing LLC.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The behaviours of bulk phonons propagating in triglycine-zinc chloride (Gly3-ZnCl2) single crystal for different polarizations of the incident and scattered beams were studied by Brillouin spectroscopy. All components of the elastic and elasto-optical tensors were determined at room temperature. Dependences of the velocities of quasi-longitudinal, transverse, and quasi-transverse phonons propagating in the planes (110), (101), and (011) on the direction of propagation are presented. © 2013 AIP Publishing LLC.
55.
Zbigniew Tylczyński, Maciej Wiesner
Long time dependence of complex dielectric permittivity in triglycine-zinc chloride crystal below room temperature Journal Article
In: Phase Transitions, vol. 86, no. 2-3, pp. 275-283, 2013, ISSN: 01411594.
@article{Tylczyński2013275,
title = {Long time dependence of complex dielectric permittivity in triglycine-zinc chloride crystal below room temperature},
author = {Zbigniew Tylczyński and Maciej Wiesner},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84872286630&doi=10.1080%2f01411594.2012.715297&partnerID=40&md5=38e66403511dec1755cb5bb3c1cebf27},
doi = {10.1080/01411594.2012.715297},
issn = {01411594},
year = {2013},
date = {2013-01-01},
journal = {Phase Transitions},
volume = {86},
number = {2-3},
pages = {275-283},
abstract = {Temperature changes in the components of complex dielectric tensor were studied in triglycine-zinc chloride crystal in the range 80-300 K. The real part of permittivity in the [001] direction shows a big jump at 234 K. The imaginary part of all dielectric components has small dispersion above this temperature. Possible phase transition in triglycine-zinc chloride crystal has been discussed. Results of measurements performed in isothermal conditions at 82 K reveal a slow rise in permittivity to its initial value measured above 234 K. This process depends on the frequency of measuring field. The JMA analysis is applied to determine the Avrami parameter. © 2013 Copyright Taylor and Francis Group, LLC.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Temperature changes in the components of complex dielectric tensor were studied in triglycine-zinc chloride crystal in the range 80-300 K. The real part of permittivity in the [001] direction shows a big jump at 234 K. The imaginary part of all dielectric components has small dispersion above this temperature. Possible phase transition in triglycine-zinc chloride crystal has been discussed. Results of measurements performed in isothermal conditions at 82 K reveal a slow rise in permittivity to its initial value measured above 234 K. This process depends on the frequency of measuring field. The JMA analysis is applied to determine the Avrami parameter. © 2013 Copyright Taylor and Francis Group, LLC.
54.
Zbigniew Tylczyński
In: Journal of Crystal Growth, vol. 382, pp. 94-95, 2013, ISSN: 00220248.
@article{Tylczyński201394,
title = {Comment on "Effect of rare earth ions on the properties of glycine phosphite single crystals" by K. Senthilkumar et al. [J. Cryst. Growth 362 (2013) 343-348]},
author = {Zbigniew Tylczyński},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84884252713&doi=10.1016%2fj.jcrysgro.2013.08.002&partnerID=40&md5=df4fd8bf7f6fd57639e20346bbf8f10d},
doi = {10.1016/j.jcrysgro.2013.08.002},
issn = {00220248},
year = {2013},
date = {2013-01-01},
journal = {Journal of Crystal Growth},
volume = {382},
pages = {94-95},
publisher = {Elsevier B.V.},
abstract = {Only saturated P-E hysteresis loop informs about ferroelectric properties of crystals. Elliptical loops presented in commented paper arise from the electric energy loss when the samples are subjected to ac field. The ac dielectric current in the crystals doped with the trivalent rare earth ions is a few times larger in comparison to those for pure GPI crystal. GPI crystal has centrosymmetric space group in paraelectric phase, so the piezoelectric property measured at RT is artefact. Foreign ions lying in the interstitial places do not compress the elementary cell volume. © 2013 Elsevier B.V.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Only saturated P-E hysteresis loop informs about ferroelectric properties of crystals. Elliptical loops presented in commented paper arise from the electric energy loss when the samples are subjected to ac field. The ac dielectric current in the crystals doped with the trivalent rare earth ions is a few times larger in comparison to those for pure GPI crystal. GPI crystal has centrosymmetric space group in paraelectric phase, so the piezoelectric property measured at RT is artefact. Foreign ions lying in the interstitial places do not compress the elementary cell volume. © 2013 Elsevier B.V.
53.
B R Srinivasan, Zbigniew Tylczyński, V S Nadkarni
In: Optical Materials, vol. 35, no. 8, pp. 1616-1618, 2013, ISSN: 09253467.
@article{Srinivasan20131616,
title = {Comment on 'synthesis, growth, structural, spectral, linear and nonlinear optical and mechanical studies of a novel organic NLO single crystal 4-bromo 4-nitrostilbene (BONS) for nonlinear optical applications'},
author = {B R Srinivasan and Zbigniew Tylczyński and V S Nadkarni},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84878316162&doi=10.1016%2fj.optmat.2013.03.029&partnerID=40&md5=6186d191c4080c3296a83bed87ad58a4},
doi = {10.1016/j.optmat.2013.03.029},
issn = {09253467},
year = {2013},
date = {2013-01-01},
journal = {Optical Materials},
volume = {35},
number = {8},
pages = {1616-1618},
publisher = {Elsevier B.V.},
abstract = {We argue that the recently reported compound 4-bromo-4′-nitrostilbene (1) is not a novel organic NLO crystal as claimed by Dinakaran, Kalainathan, Opt. Mater. 35 (2013) 898-903, but instead a well known compound whose characterization data and SHG efficiency are well documented in literature. The title paper is completely erroneous. Two more similar erroneous papers by the same authors are also commented. © 2013 Elsevier B.V. All rights reserved.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We argue that the recently reported compound 4-bromo-4′-nitrostilbene (1) is not a novel organic NLO crystal as claimed by Dinakaran, Kalainathan, Opt. Mater. 35 (2013) 898-903, but instead a well known compound whose characterization data and SHG efficiency are well documented in literature. The title paper is completely erroneous. Two more similar erroneous papers by the same authors are also commented. © 2013 Elsevier B.V. All rights reserved.
2012
52.
Mykhaylo Sokolovskyy, Jarosław W Kłos, Sławomir Mamica, Maciej Krawczyk
Calculation of the spin-wave spectra in planar magnonic crystals with metallic overlayers Journal Article
In: Journal of Applied Physics, vol. 111, pp. 07C515, 2012.
@article{met_overl,
title = {Calculation of the spin-wave spectra in planar magnonic crystals with metallic overlayers},
author = {Mykhaylo Sokolovskyy and Jarosław W Kłos and Sławomir Mamica and Maciej Krawczyk},
url = {http://jap.aip.org/resource/1/japiau/v111/i7/p07C515_s1},
doi = {http://dx.doi.org/10.1063/1.3677661},
year = {2012},
date = {2012-01-01},
journal = {Journal of Applied Physics},
volume = {111},
pages = {07C515},
abstract = {Planar one-dimensional magnonic crystals of nanoscale lattice constant having different types of overlayers, dielectric and metallic, are studied. The dynamics of magnetization is described by the Landau-Lifshitz equation, which is solved using the plane-wave method. The calculations are performed with the nonuniform dynamic dipolar field. At the same time, the finite thickness of the studied structures is taken into account. New possibilities for shaping dispersion relations of spin waves and magnonic bandgaps in planar magnonic crystals by adding metallic/dielectric overlayers on the top of it are found.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Planar one-dimensional magnonic crystals of nanoscale lattice constant having different types of overlayers, dielectric and metallic, are studied. The dynamics of magnetization is described by the Landau-Lifshitz equation, which is solved using the plane-wave method. The calculations are performed with the nonuniform dynamic dipolar field. At the same time, the finite thickness of the studied structures is taken into account. New possibilities for shaping dispersion relations of spin waves and magnonic bandgaps in planar magnonic crystals by adding metallic/dielectric overlayers on the top of it are found.
51.
S Tacchi, G Duerr, Jarosław W Kłos, M Madami, S Neusser, G Gubbiotti, G Carlotti, Maciej Krawczyk, D Grundler
Forbidden band gaps in the spin-wave spectrum of a two-dimensional bicomponent magnonic crystal Journal Article
In: Physical Review Letters, vol. 109, pp. 137202, 2012.
@article{bicomponent_2D,
title = {Forbidden band gaps in the spin-wave spectrum of a two-dimensional bicomponent magnonic crystal},
author = {S Tacchi and G Duerr and Jarosław W Kłos and M Madami and S Neusser and G Gubbiotti and G Carlotti and Maciej Krawczyk and D Grundler},
url = {http://prl.aps.org/pdf/PRL/v109/i13/e137202},
doi = {10.1103/PhysRevLett.109.137202},
year = {2012},
date = {2012-01-01},
journal = {Physical Review Letters},
volume = {109},
pages = {137202},
abstract = {The spin-wave band structure of a two-dimensional bicomponent magnonic crystal, consisting of Co nanodisks partially embedded in a Permalloy thin film, is experimentally investigated along a highsymmetry direction by Brillouin light scattering. The eigenfrequencies and scattering cross sections are interpreted using plane wave method calculations and micromagnetic simulations. At the boundary of both the first and the second Brillouin zones, we measure a forbidden frequency gap whose width depends on the magnetic contrast between the constituent materials. The modes above and below the gap exhibit resonant spin-precession amplitudes in the complementary regions of periodically varying magnetic parameters. Our findings are key to advance both the physics and the technology of band gap engineering in magnonics.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The spin-wave band structure of a two-dimensional bicomponent magnonic crystal, consisting of Co nanodisks partially embedded in a Permalloy thin film, is experimentally investigated along a highsymmetry direction by Brillouin light scattering. The eigenfrequencies and scattering cross sections are interpreted using plane wave method calculations and micromagnetic simulations. At the boundary of both the first and the second Brillouin zones, we measure a forbidden frequency gap whose width depends on the magnetic contrast between the constituent materials. The modes above and below the gap exhibit resonant spin-precession amplitudes in the complementary regions of periodically varying magnetic parameters. Our findings are key to advance both the physics and the technology of band gap engineering in magnonics.
50.
Yu S Dadoenkova, N N Dadoenkova, I L Lyubchanskii, Mykhaylo Sokolovskyy, Jarosław W Kłos, Javier Romero Vivas, Maciej Krawczyk
Huge Goos-Hänchen effect for spin waves: A promising tool for study magnetic properties at interfaces Journal Article
In: Applied Physics Letters, vol. 101, no. 4, pp. 042404, 2012, (The following article appeared in Applied Physics Letters Vol.101, Issue 4) and may be found at http://link.aip.org/link/?APL/101/042404).
@article{GHc,
title = {Huge Goos-Hänchen effect for spin waves: A promising tool for study magnetic properties at interfaces},
author = {Yu S Dadoenkova and N N Dadoenkova and I L Lyubchanskii and Mykhaylo Sokolovskyy and Jarosław W Kłos and Javier Romero Vivas and Maciej Krawczyk},
url = {http://apl.aip.org/resource/1/applab/v101/i4/p042404_s1},
doi = {10.1063/1.4738987},
year = {2012},
date = {2012-01-01},
journal = {Applied Physics Letters},
volume = {101},
number = {4},
pages = {042404},
note = {The following article appeared in Applied Physics Letters Vol.101, Issue 4) and may be found at http://link.aip.org/link/?APL/101/042404},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
49.
Javier Romero Vivas, Sławomir Mamica, Maciej Krawczyk, V V Kruglyak
Investigation of spin wave damping in three-dimensional magnonic crystals using the plane wave method Journal Article
In: Physical Review B, vol. 86, no. 14, pp. 144417, 2012.
@article{pv,
title = {Investigation of spin wave damping in three-dimensional magnonic crystals using the plane wave method},
author = {Javier Romero Vivas and Sławomir Mamica and Maciej Krawczyk and V V Kruglyak},
url = {http://link.aps.org/doi/10.1103/PhysRevB.86.144417},
doi = {10.1103/PhysRevB.86.144417},
year = {2012},
date = {2012-01-01},
journal = {Physical Review B},
volume = {86},
number = {14},
pages = {144417},
abstract = {The Landau-Lifshitz equation with a scalar damping constant predicts that the damping of spin waves propagating in an infinite homogeneous magnetic medium does not depend on the direction of propagation. This is not the case in materials with a periodic arrangement of magnetic constituents (known as magnonic crystals). In this paper, the plane wave method is extended to include damping in the calculation of the dispersion and relaxation of spin waves in three-dimensional magnonic crystals. A model material system is introduced and calculations are then presented for magnonic crystals realized in the direct and inverted structure and for two different filling fractions. The ability of magnonic crystals to support the propagation of spin waves is characterized in terms of a figure of merit, defined as the ratio of the spin wave frequency to the decay constant. The calculations reveal that in magnonic crystals with a modulated value of the relaxation constant, the figure of merit depends strongly on the frequency and wave vector of the spin waves, with the dependence determined by the spatial distribution of the spin wave amplitude within the unit cell of the magnonic crystal. Bands and directions of exceptionally long spin wave propagation have been identified. The results are also discussed in terms of the use of magnonic crystals as metamaterials with designed magnetic permeability.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The Landau-Lifshitz equation with a scalar damping constant predicts that the damping of spin waves propagating in an infinite homogeneous magnetic medium does not depend on the direction of propagation. This is not the case in materials with a periodic arrangement of magnetic constituents (known as magnonic crystals). In this paper, the plane wave method is extended to include damping in the calculation of the dispersion and relaxation of spin waves in three-dimensional magnonic crystals. A model material system is introduced and calculations are then presented for magnonic crystals realized in the direct and inverted structure and for two different filling fractions. The ability of magnonic crystals to support the propagation of spin waves is characterized in terms of a figure of merit, defined as the ratio of the spin wave frequency to the decay constant. The calculations reveal that in magnonic crystals with a modulated value of the relaxation constant, the figure of merit depends strongly on the frequency and wave vector of the spin waves, with the dependence determined by the spatial distribution of the spin wave amplitude within the unit cell of the magnonic crystal. Bands and directions of exceptionally long spin wave propagation have been identified. The results are also discussed in terms of the use of magnonic crystals as metamaterials with designed magnetic permeability.
48.
Sławomir Mamica, Maciej Krawczyk, Mykhaylo Sokolovskyy, Javier Romero Vivas
Large magnonic band gaps and spectra evolution in three-dimensional magnonic crystals based on magnetoferritin nanoparticles Journal Article
In: Physical Review B, vol. 86, no. 14, pp. 144402, 2012.
@article{Mamica2012PRB,
title = {Large magnonic band gaps and spectra evolution in three-dimensional magnonic crystals based on magnetoferritin nanoparticles},
author = {Sławomir Mamica and Maciej Krawczyk and Mykhaylo Sokolovskyy and Javier Romero Vivas},
doi = {10.1103/PhysRevB.86.144402},
year = {2012},
date = {2012-01-01},
journal = {Physical Review B},
volume = {86},
number = {14},
pages = {144402},
abstract = {We study magnonic crystals based on magnetoferritin nanoparticles. These nanoparticles self-assemble to form crystals of highly ordered fcc structure with a lattice constant of ten-odd nanometers. Filling the interparticle space by a ferromagnetic material should stabilize the ferromagnetic order in such a crystal at room temperature. We use the plane wave method to demonstrate that the introduction of a ferromagnetic matrix can also lead to the opening of a complete band gap, referred to as a magnonic band gap, in the spin-wave spectrum. We use a model based on a homogeneous medium with effective parameters to interpret the characteristics of the obtained spin-wave spectra in the longwave limit. We also study in detail thewidth of the band gap and its central frequency versus the matrix material and the lattice constant. The occurrence of a maximum width in the lattice-constant dependence is shown to be closely related to the specific behavior of the dynamic magnetization profiles of the lowest excitations in the spin-wave spectrum. On the basis of our results we determine the conditions conducive to the occurrence of a complete magnonic band gap. We also show that the crystallographic structure and the lattice constant of the crystals produced by the protein crystallization technique are almost optimized for the occurrence of a magnonic band gap.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We study magnonic crystals based on magnetoferritin nanoparticles. These nanoparticles self-assemble to form crystals of highly ordered fcc structure with a lattice constant of ten-odd nanometers. Filling the interparticle space by a ferromagnetic material should stabilize the ferromagnetic order in such a crystal at room temperature. We use the plane wave method to demonstrate that the introduction of a ferromagnetic matrix can also lead to the opening of a complete band gap, referred to as a magnonic band gap, in the spin-wave spectrum. We use a model based on a homogeneous medium with effective parameters to interpret the characteristics of the obtained spin-wave spectra in the longwave limit. We also study in detail thewidth of the band gap and its central frequency versus the matrix material and the lattice constant. The occurrence of a maximum width in the lattice-constant dependence is shown to be closely related to the specific behavior of the dynamic magnetization profiles of the lowest excitations in the spin-wave spectrum. On the basis of our results we determine the conditions conducive to the occurrence of a complete magnonic band gap. We also show that the crystallographic structure and the lattice constant of the crystals produced by the protein crystallization technique are almost optimized for the occurrence of a magnonic band gap.
47.
V V Kruglyak, M Dvornik, R V Mikhaylovskiy, O Dmytriiev, G Gubbiotti, S Tacchi, M Madami, G Carlotti, F Montoncello, L Giovannini, R Zivieri, Jarosław W Kłos, Mykhaylo Sokolovskyy, Sławomir Mamica, Maciej Krawczyk, M Okuda, J C Eloi, Ward S Jones, W Schwarzacher, T Schwarze, F Brandl, D Grundler, D V Berkov, E Semenova, N Gorn
Metamaterial/Magnonic Metamaterials Book Chapter
In: Chapter 14, pp. 341-370, INTECH, 2012, ISBN: 978-953-51-0591-6.
@inbook{magnonics_mater,
title = {Metamaterial/Magnonic Metamaterials},
author = {V V Kruglyak and M Dvornik and R V Mikhaylovskiy and O Dmytriiev and G Gubbiotti and S Tacchi and M Madami and G Carlotti and F Montoncello and L Giovannini and R Zivieri and Jarosław W Kłos and Mykhaylo Sokolovskyy and Sławomir Mamica and Maciej Krawczyk and M Okuda and J C Eloi and Ward S Jones and W Schwarzacher and T Schwarze and F Brandl and D Grundler and D V Berkov and E Semenova and N Gorn},
url = {http://www.intechopen.com/books/metamaterial/magnonic-metamaterials},
doi = {DOI: 10.5772/37454},
isbn = {978-953-51-0591-6},
year = {2012},
date = {2012-01-01},
pages = {341-370},
publisher = {INTECH},
chapter = {14},
keywords = {},
pubstate = {published},
tppubtype = {inbook}
}
46.
S Tacchi, B Botters, Jarosław W Kłos, Mykhaylo Sokolovskyy, Maciej Krawczyk, G Gubbiotti, G Carlotti, A O Adeyeye, S Neusser, D Grundler
Mode conversion from quantized to propagating spin waves in a rhombic antidot lattice supporting spin wave nanochannels Journal Article
In: Physical Review B, vol. 86, pp. 014417, 2012.
@article{magnj,
title = {Mode conversion from quantized to propagating spin waves in a rhombic antidot lattice supporting spin wave nanochannels},
author = {S Tacchi and B Botters and Jarosław W Kłos and Mykhaylo Sokolovskyy and Maciej Krawczyk and G Gubbiotti and G Carlotti and A O Adeyeye and S Neusser and D Grundler},
url = {http://prb.aps.org/abstract/PRB/v86/i1/e014417},
doi = {10.1103/PhysRevB.86.014417},
year = {2012},
date = {2012-01-01},
journal = {Physical Review B},
volume = {86},
pages = {014417},
abstract = {We report spin wave excitations in a nanopatterned antidot lattice fabricated from a 30-nm thick Ni80Fe20 film. The 250-nm-wide circular holes are arranged in a rhombic unit cell with a lattice constant of 400 nm. By Brillouin light scattering, we find that quantized spin wave modes transform to propagating ones and vice versa by changing the in-plane orientation of the applied magnetic field H by 30∘. Spin waves of either negative or positive group velocity are found. In the latter case, they propagate in narrow channels exhibiting a width of below 100 nm. We use the plane wave method to calculate the spin wave dispersions for the two relevant orientations of H. The theory allows us to explain the wave-vector-dependent characteristics of the prominent modes. Allowed minibands are formed for selected modes only for specific orientations of H and wave vector. The results are important for applications such as spin wave filters and interconnected waveguides in the emerging field of magnonics where the control of spin wave propagation on the nanoscale is key.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We report spin wave excitations in a nanopatterned antidot lattice fabricated from a 30-nm thick Ni80Fe20 film. The 250-nm-wide circular holes are arranged in a rhombic unit cell with a lattice constant of 400 nm. By Brillouin light scattering, we find that quantized spin wave modes transform to propagating ones and vice versa by changing the in-plane orientation of the applied magnetic field H by 30∘. Spin waves of either negative or positive group velocity are found. In the latter case, they propagate in narrow channels exhibiting a width of below 100 nm. We use the plane wave method to calculate the spin wave dispersions for the two relevant orientations of H. The theory allows us to explain the wave-vector-dependent characteristics of the prominent modes. Allowed minibands are formed for selected modes only for specific orientations of H and wave vector. The results are important for applications such as spin wave filters and interconnected waveguides in the emerging field of magnonics where the control of spin wave propagation on the nanoscale is key.
45.
Maciej Krawczyk, Mykhaylo Sokolovskyy, Jarosław W Kłos, Sławomir Mamica
On the formulation of the exchange field in the Landau-Lifshitz equation for spin-wave calculation in magnonic crystals Journal Article
In: Advances in Condensed Matter Physics, vol. 2012, 2012.
@article{2i,
title = {On the formulation of the exchange field in the Landau-Lifshitz equation for spin-wave calculation in magnonic crystals},
author = {Maciej Krawczyk and Mykhaylo Sokolovskyy and Jarosław W Kłos and Sławomir Mamica},
url = {http://www.hindawi.com/journals/acmp/2012/764783/},
doi = {10.1155/2012/764783},
year = {2012},
date = {2012-01-01},
journal = {Advances in Condensed Matter Physics},
volume = {2012},
abstract = {The calculation of the magnonic spectra using the plane-wave method has limitations, the origin of which lies in the formulation of the effective magnetic field term in the equation of motion (the Landau-Lifshitz equation) for composite media. According to ideas of the plane-wave method the system dynamics is described in terms of plane waves (a superposition of a number of plane waves), which are continuous functions and propagate throughout the medium. Since in magnonic crystals the sought-for superposition of plane waves represents the dynamic magnetization, the magnetic boundary conditions on the interfaces between constituent materials should be inherent in the Landau-Lifshitz equations. In this paper we present the derivation of the two expressions for the exchange field known from the literature. We start from the Heisenberg model and use a linear approximation and take into account the spacial dependence of saturation magnetization and exchange constant present in magnetic composites. We discuss the magnetic boundary conditions included in the presented formulations of the exchange field and elucidate their effect on spin-wave modes and their spectra in one- and two-dimensional planar magnonic crystals from plane-wave calculations.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The calculation of the magnonic spectra using the plane-wave method has limitations, the origin of which lies in the formulation of the effective magnetic field term in the equation of motion (the Landau-Lifshitz equation) for composite media. According to ideas of the plane-wave method the system dynamics is described in terms of plane waves (a superposition of a number of plane waves), which are continuous functions and propagate throughout the medium. Since in magnonic crystals the sought-for superposition of plane waves represents the dynamic magnetization, the magnetic boundary conditions on the interfaces between constituent materials should be inherent in the Landau-Lifshitz equations. In this paper we present the derivation of the two expressions for the exchange field known from the literature. We start from the Heisenberg model and use a linear approximation and take into account the spacial dependence of saturation magnetization and exchange constant present in magnetic composites. We discuss the magnetic boundary conditions included in the presented formulations of the exchange field and elucidate their effect on spin-wave modes and their spectra in one- and two-dimensional planar magnonic crystals from plane-wave calculations.
44.
Wojciech Śmigaj, B Gralak
Semianalytical design of antireflection gratings for photonic crystals Journal Article
In: Physical Review B, vol. 85, pp. 035114, 2012.
@article{antiref_photonic,
title = {Semianalytical design of antireflection gratings for photonic crystals},
author = {Wojciech Śmigaj and B Gralak},
url = {http://link.aps.org/doi/10.1103/PhysRevB.85.035114},
doi = {10.1103/PhysRevB.85.035114},
year = {2012},
date = {2012-01-01},
journal = {Physical Review B},
volume = {85},
pages = {035114},
abstract = {This article concerns the design of antireflection structures which, placed on a photonic crystal surface, significantly diminish the fraction of energy lost to reflected waves. After a review of the classes of these structures proposed to date, a new method is presented in detail for the design of antireflection gratings operating in a wide range of angles of incidence. The proposed algorithm is illustrated by means of several examples, showing the advantages and limitations.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This article concerns the design of antireflection structures which, placed on a photonic crystal surface, significantly diminish the fraction of energy lost to reflected waves. After a review of the classes of these structures proposed to date, a new method is presented in detail for the design of antireflection gratings operating in a wide range of angles of incidence. The proposed algorithm is illustrated by means of several examples, showing the advantages and limitations.
43.
F Montoncello, L Giovannini, Maciej Krawczyk
Spin wave localization and softening in rod-shaped magnonic crystals with different terminations Journal Article
In: Journal of Applied Physics, vol. 112, pp. 033911, 2012, (The following article appeared in Applied Physics Letters Vol.101, Issue 4) and may be found at http://link.aip.org/link/?APL/101/042404).
@article{12_1b,
title = {Spin wave localization and softening in rod-shaped magnonic crystals with different terminations},
author = {F Montoncello and L Giovannini and Maciej Krawczyk},
url = {http://jap.aip.org/resource/1/japiau/v112/i3/p033911_s1},
doi = {dx.doi.org/10.1063/1.4743003},
year = {2012},
date = {2012-01-01},
journal = {Journal of Applied Physics},
volume = {112},
pages = {033911},
abstract = {The spin dynamics of simple cubic arrays of magnetic dipoles with the shape of elongated prisms is investigated in dependence of their terminations (flat or cusp) and of the applied field. We used two different calculation approaches: in the first, we solve the Landau-Lisfshits equation of motion of planar arrangements of magnetic dipoles, the static magnetization of the array is supposed to be uniform along the direction of the applied field, and the calculated modes have nodal planes perpendicular to the magnetization. In the second approach, we use the dynamical matrix method, which is a micromagnetic method, considers the exact (non-uniform) magnetic equilibrium configuration, and returns the complete set of magnetic eigenvalues/eigenmodes. Calculations show the existence of modes with different localization: low frequency modes, localized at the prism ends, and high frequency bulk modes, including the fundamental or quasi-uniform mode. We studied the internal field profile as a function of the termination details, the localization of spin modes, in particular of the lowest frequency mode, and the space resolved density of states. Finally, we address the soft modes of these systems, showing their frequency vs. applied field behavior in relation to the discontinuity of the magnetization curve, and investigating the symmetry transfer from the soft mode profile to the static magnetization, with possible applications.},
note = {The following article appeared in Applied Physics Letters Vol.101, Issue 4) and may be found at http://link.aip.org/link/?APL/101/042404},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The spin dynamics of simple cubic arrays of magnetic dipoles with the shape of elongated prisms is investigated in dependence of their terminations (flat or cusp) and of the applied field. We used two different calculation approaches: in the first, we solve the Landau-Lisfshits equation of motion of planar arrangements of magnetic dipoles, the static magnetization of the array is supposed to be uniform along the direction of the applied field, and the calculated modes have nodal planes perpendicular to the magnetization. In the second approach, we use the dynamical matrix method, which is a micromagnetic method, considers the exact (non-uniform) magnetic equilibrium configuration, and returns the complete set of magnetic eigenvalues/eigenmodes. Calculations show the existence of modes with different localization: low frequency modes, localized at the prism ends, and high frequency bulk modes, including the fundamental or quasi-uniform mode. We studied the internal field profile as a function of the termination details, the localization of spin modes, in particular of the lowest frequency mode, and the space resolved density of states. Finally, we address the soft modes of these systems, showing their frequency vs. applied field behavior in relation to the discontinuity of the magnetization curve, and investigating the symmetry transfer from the soft mode profile to the static magnetization, with possible applications.
42.
Sławomir Mamica, Maciej Krawczyk, Jarosław W Kłos
Spin-wave band structure in 2D magnonic crystals with elliptically shaped scattering centres Journal Article
In: Advances in Condensed Matter Physics, vol. 2012, pp. 1-6, 2012.
@article{12d,
title = {Spin-wave band structure in 2D magnonic crystals with elliptically shaped scattering centres},
author = {Sławomir Mamica and Maciej Krawczyk and Jarosław W Kłos},
url = {http://www.hindawi.com/journals/acmp/2012/161387/abs/},
doi = {10.1155/2012/161387},
year = {2012},
date = {2012-01-01},
journal = {Advances in Condensed Matter Physics},
volume = {2012},
pages = {1-6},
abstract = {Spin waves in 2D periodic magnetic nanocomposites are studied by means of the plane wave method. The effect of the ellipticity
and in-plane rotation of the scattering centers on the band structure is investigated, to indicate new possibilities of fine tuning of
spin-wave filter passbands.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Spin waves in 2D periodic magnetic nanocomposites are studied by means of the plane wave method. The effect of the ellipticity
and in-plane rotation of the scattering centers on the band structure is investigated, to indicate new possibilities of fine tuning of
spin-wave filter passbands.
and in-plane rotation of the scattering centers on the band structure is investigated, to indicate new possibilities of fine tuning of
spin-wave filter passbands.
41.
Sławomir Mamica, J-C S Lévy, Maciej Krawczyk, P Depondt
Stability of the Landau state in square two-dimensional magnetic nanorings Journal Article
In: Journal of Applied Physics, vol. 112, pp. 043901, 2012.
@article{Mamica2012JAP,
title = {Stability of the Landau state in square two-dimensional magnetic nanorings},
author = {Sławomir Mamica and J-C S Lévy and Maciej Krawczyk and P Depondt},
doi = {10.1063/1.4745875},
year = {2012},
date = {2012-01-01},
journal = {Journal of Applied Physics},
volume = {112},
pages = {043901},
abstract = {We use a microscopic theory taking into account dipolar and nearest-neighbour exchange interactions to explore spin-wave excitations in two-dimensional square-shaped magnetic nanorings with the Landau state assumed as a magnetic state. From the spin-wave spectra, we determine the range of the dipolar-to-exchange interaction ratio in which the assumed state is stable. Various types of localized spin waves prove responsible for the transition to a new magnetic configuration. We found the transition forced by predominating exchange interactions sizeindependent in a wide range of both external and internal size of the ring.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We use a microscopic theory taking into account dipolar and nearest-neighbour exchange interactions to explore spin-wave excitations in two-dimensional square-shaped magnetic nanorings with the Landau state assumed as a magnetic state. From the spin-wave spectra, we determine the range of the dipolar-to-exchange interaction ratio in which the assumed state is stable. Various types of localized spin waves prove responsible for the transition to a new magnetic configuration. We found the transition forced by predominating exchange interactions sizeindependent in a wide range of both external and internal size of the ring.
40.
P Nowak, Maciej Krawczyk
The effect of interface modulation on phononic band gaps for longitudinal Journal Article
In: Journal of Applied Physics, vol. 111, pp. 104312, 2012.
@article{11c,
title = {The effect of interface modulation on phononic band gaps for longitudinal},
author = {P Nowak and Maciej Krawczyk},
url = {http://jap.aip.org/resource/1/JAPIAU/v111/i10},
doi = {http://dx.doi.org/10.1063/1.4720467},
year = {2012},
date = {2012-01-01},
journal = {Journal of Applied Physics},
volume = {111},
pages = {104312},
abstract = {We present the results of our theoretical investigation of the effect of a periodic interface modulation on the longitudinal vibrational modes in one-dimensional phononic crystals. Based on the plane wave method and the finite difference time domain method, our calculations show that the bottom and top of the first phononic gap can be controlled independently by adjusting the modulation introduced. The effective acoustic impedance of the modulated layers is demonstrated to be of key importance for the opening of phononic energy gaps. Band gaps for longitudinal modes can be expected to occur in a large range of interface inhomogeneity. The shape of the modulation proves not to have any significant effect on the investigated properties.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We present the results of our theoretical investigation of the effect of a periodic interface modulation on the longitudinal vibrational modes in one-dimensional phononic crystals. Based on the plane wave method and the finite difference time domain method, our calculations show that the bottom and top of the first phononic gap can be controlled independently by adjusting the modulation introduced. The effective acoustic impedance of the modulated layers is demonstrated to be of key importance for the opening of phononic energy gaps. Band gaps for longitudinal modes can be expected to occur in a large range of interface inhomogeneity. The shape of the modulation proves not to have any significant effect on the investigated properties.