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Найдено документов в текущей БД: 17

    Partial restoration of the wave spectrum of a superlattice due to cross correlations between one- and three-dimensional inhomogeneities
/ V. A. Ignatchenko, Y. I. Mankov // Phys. Rev. B. - 2007. - Vol. 75, Is. 23. - Ст. 235422, DOI 10.1103/PhysRevB.75.235422. - Cited References: 32 . - ISSN 1098-0121
РУБ Physics, Condensed Matter

Аннотация: Effects of cross correlations between one-dimensional (1D) and three-dimensional (3D) random inhomogeneities on the wave spectrum in sinusoidal superlattices are studied theoretically. The situation when the gap in the spectrum (the forbidden zone) at the first Brillouin zone boundary of the superlattice is closed under the action of the 1D inhomogeneities is considered. The phenomenon of the partial opening of this gap is found when the 3D inhomogeneities cross correlated with the 1D inhomogeneities add to the superlattice. The appearance of the logarithmic resonance in the center of the forbidden zone under the action of the cross correlations is shown. The physical nature of the effects in the wave spectrum of the superlattice that are caused by the cross correlations and the relation of these effects with the asymptotic properties of the correlation function of inhomogeneities are discussed.

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Держатели документа:
SB RAS, LV Kirensky Inst Phys, Krasnoyarsk 660036, Russia
ИФ СО РАН
L. V. Kirensky Institute of Physics, SB RAS, 660036 Krasnoyarsk, Russian Federation

Доп.точки доступа:
Mankov, Y. I.; Игнатченко, Вальтер Алексеевич

    Effect of the correlation properties of one- and three-dimensional inhomogeneities on the high-frequency magnetic susceptibility of sinusoidal superlattices
/ V. A. Ignatchenko, Y. I. Mankov // Phys. Solid State. - 2005. - Vol. 47, Is. 3. - P. 587-594, DOI 10.1134/1.1884725. - Cited References: 29 . - ISSN 1063-7834
РУБ Physics, Condensed Matter

Аннотация: The effect of one-(1D) and three-dimensional (3D) inhomogeneities on the high-frequency magnetic susceptibility at the boundary of the first Brillouin zone of a ferromagnetic superlattice is studied. The study is performed with an earlier developed method of random spatial modulation (RSM) of the superlattice period. In this method, structural inhomogeneities are described in terms of the random-phase model, in which the phase depends on three coordinates in the general case. The frequency spacing Delta v(m) between two peaks in the imaginary part of the averaged Green's function, which characterizes the gap width in the frequency spectrum at the boundary of the Brillouin zone, is calculated as a function of both the root-mean-square fluctuations gamma(i) and the correlation wavenumbers eta(i) of phase inhomogeneities (i = 1 and 3 for 1D and 3D inhomogeneities, respectively). The function Delta v(m)(gamma(1), eta(1)) for 1D inhomogeneities is shown to be symmetric with respect to inter- changing the variables gamma(1)(2) and eta(1), whereas the function Delta v(m)(gamma(3), eta(3)) for 3D inhomogeneities is strongly asym- metric with respect to interchanging gamma(3)(2) eta(3). This effect is associated with the difference in form between the correlation functions of 1D and 3D inhomogeneities and can be used to determine the dimensionality of inhomogeneities from the results of spectral studies of such superlattices. (c) 2005 Pleiades Publishing, Inc.

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Держатели документа:
Russian Acad Sci, Kirensky Inst Phys, Siberian Div, Krasnoyarsk 660036, Russia
ИФ СО РАН
Kirensky Institute of Physics, Siberian Division, Russian Academy of Sciences, Krasnoyarsk, Akademgorodok, 660036, Russian Federation

Доп.точки доступа:
Mankov, Y. I.; Игнатченко, Вальтер Алексеевич

    Waves in a superlattice with arbitrary interlayer boundary thickness
/ V. A. Ignatchenko, O. N. Laletin // Phys. Solid State. - 2004. - Vol. 46, Is. 12. - P. 2292-2300, DOI 10.1134/1.1841396. - Cited References: 34 . - ISSN 1063-7834
РУБ Physics, Condensed Matter

Аннотация: The transmittance D(omega), reflectance R(omega), and dispersion omega(k) are investigated for waves of various nature propagating through a one-dimensional superlattice (multilayer structure) with arbitrary thickness of the interlayer boundary. The dependences of the band gap widths Deltaomega(m) and their positions in the wave spectrum of the superlattice on the interlayer boundary thickness d and the band number m are calculated. Calculations are performed in terms of the modified coupled-mode theory (MCMT) using the frequency dependence of R(omega), as well as in the framework of perturbation theory using the function omega(k), which made it possible to estimate the accuracy of the MCMT method; the MCMT method is found to have a high accuracy in calculating the band gap widths and a much lower accuracy in determining the gap positions. It is shown that the m dependence of Deltaomega(m) for electromagnetic (or elastic) waves is different from that for spin waves. Furthermore, the widths of the band gaps with m = 1 and 2 are practically independent of d, whereas the widths of all gaps for m 2 depend strongly on d. Experimental measurements of these dependences allow one to determine the superlattice interface thicknesses by using spectral methods. (C) 2004 MAIK "Nauka/Interperiodica".

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Держатели документа:
Russian Acad Sci, Siberian Div, LV Kirensky Phys Inst, Krasnoyarsk 660036, Russia
Krasnoyarsk State Univ, Krasnoyarsk 660041, Russia
ИФ СО РАН
Kirensky Institute of Physics, Siberian Division, Russian Academy of Sciences, Akademgorodok, Krasnoyarsk 660036, Russian Federation
Krasnoyarsk State University, Krasnoyarsk, 660041, Russian Federation

Доп.точки доступа:
Laletin, O. N.; Игнатченко, Вальтер Алексеевич

    Effects of the dimensionality of inhomogeneities on the wave spectrum of superlattices
/ V. A. Ignatchenko, Y. I. Mankov, A. A. Maradudin // Phys. Rev. B. - 2003. - Vol. 68, Is. 2. - Ст. 24209, DOI 10.1103/PhysRevB.68.024209. - Cited References: 26 . - ISSN 1098-0121
РУБ Physics, Condensed Matter

Аннотация: Dependences of the dispersion laws and damping of waves in an initially sinusoidal superlattice on the dimensionality of inhomogeneities modulating the period of the superlattice are studied. The cases of one- and three-dimensional modulations, as well as modulation by a mixture of inhomogeneities of both of these dimensionalities, are considered. The correlation function of the superlattice K(r) has the form of a product of the same periodic function and a decreasing function that is significantly different for these different cases. For r -- infinity the decreasing function goes to zero for the one-dimensional inhomogeneities and to a nonzero asymptote for the three-dimensional ones. Consequently, the transition from the disordered to ordered states is accompanied in the three-dimensional case not only by an increase of the correlation radius as in the one-dimensional case, but also by a change in the relationship between the volumes of the superlattices with finite and infinite correlation radii. The decreasing part of the correlation function for the mixture of inhomogeneities of different dimensionalities has the form of a product of the decreasing parts of the correlation functions of the components of the mixture. This leads to the nonadditivity of the contributions of the components of different dimensionalities to the resulting modification of the parameters of the wave spectrum that are due to the inhomogeneities (the damping of waves for the mixture of these components is smaller than the sum of the dampings of the components, the maximum gap in the spectrum corresponds to the simultaneous presence of both components, and so on).

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Держатели документа:
LV Kirenskii Inst Phys, Krasnoyarsk 660036, Russia
Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA
ИФ СО РАН

Доп.точки доступа:
Mankov, Y. I.; Maradudin, A. A.; Игнатченко, Вальтер Алексеевич

    Waves in a superlattice with anisotropic inhomogeneities
/ V. A. Ignatchenko, A. A. Maradudin, A. V. Poszdnyakov // JETP Letters. - 2003. - Vol. 78, Is. 9. - P. 592-596, DOI 10.1134/1.1641491. - Cited References: 28 . - ISSN 0021-3640
РУБ Physics, Multidisciplinary

Аннотация: Dependences of the dispersion laws and damping of waves in an initially sinusoidal superlattice on inhomogeneities with anisotropic correlation properties are studied for the first time. The period of the superlattice is modulated by the random function described by the anisotropic correlation function K-phi(r) that has different correlation radii, k(parallel toparallel to)(-1) and k(perpendicular to)(-1), along the axis of the superlattice z and in the plane xy, respectively. The anisotropy of the correlation is characterized by the parameter lambda = 1 - k(perpendicular to)/k(parallel toparallel to) that can change from lambda = 0 to lambda = 1 when the correlation wave number k(perpendicular to) changes from k(perpendicular to) = k(parallel toparallel to) (isotropic 3D inhomogeneities) to k(perpendicular to) = 0 (1D inhomogeneities). The correlation function of the superlattice K(r) is developed. Its decreasing part goes to the asymptote L that divides the correlation volume into two parts, characterized by finite and infinite correlation radii. The dependences of the width of the gap in the spectrum at the boundary of the Brillouin zone Deltanu and the damping of waves xi on the value of lambda are studied. It is shown that decreasing L leads to the decrease of Deltanu, and increase of xi, with the increase of lambda. (C) 2003 MAIK "Nauka / Interperiodica".

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Держатели документа:
Russian Acad Sci, LV Kirensky Phys Inst, Siberian Div, Krasnoyarsk 660036, Russia
Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA
ИФ СО РАН
Kirensky Institute of Physics, Siberian Division, Russian Academy of Sciences, Krasnoyarsk, 660036, Russian Federation
Department of Physics and Astronomy, University of California, Irvine, CA, United States

Доп.точки доступа:
Maradudin, A. A.; Poszdnyakov, A. V.; Игнатченко, Вальтер Алексеевич

    Effects of the mixture of one- and three-dimensional inhomogeneities on the wave spectrum of superlattices
/ V. A. Ignatchenko, Y. I. Mankov, A. A. Maradudin // JETP Letters. - 2003. - Vol. 77, Is. 6. - P. 285-290, DOI 10.1134/1.1577758. - Cited References: 24 . - ISSN 0021-3640
РУБ Physics, Multidisciplinary

Аннотация: Dependences of the dispersion laws and damping of waves in an initially sinusoidal superlattice on the dimensionality of inhomogeneities modulating the period of the superlattice are studied. The cases of one- and three-dimensional modulations, as well as modulation by a mixture of inhomogeneities of both of these dimensionalities, are considered. The correlation function of the superlattice K(r) has the form of a product of the same periodic function and a decreasing function that is significantly different for these different cases. The decreasing part of the correlation function for the mixture of inhomogeneities of different dimensionalities has the form of a product of the decreasing parts of the correlation functions of the components of the mixture. This leads to the nonadditivity of the contributions of the components of different dimensionalities to the resulting modification of the parameters of the wave spectrum that are due to the inhomogeneities (the damping of waves for the mixture of these components is smaller than the sum of the dampings of the components, the maximum gap in the spectrum corresponds to the simultaneous presence of both components of the mixture, not only of the three-dimensional inhomogeneities). (C) 2003 MAIK "Nauka / Interperiodica".

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Держатели документа:
LV Kirenskii Inst Phys, Krasnoyarsk 660036, Russia
Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA
ИФ СО РАН
Kirensky Institute of Physics, Krasnoyarsk, 660036, Russian Federation
Department of Physics and Astronomy, University of California, Irvine, CA 92697, United States

Доп.точки доступа:
Mankov, Y. I.; Maradudin, A. A.; Игнатченко, Вальтер Алексеевич

    Effects of one- and three-dimensional inhomogeneities on the wave spectrum of multilayers with finite interface thicknesses
/ V. A. Ignatchenko, Y. I. Mankov, A. A. Maradudin // Phys. Rev. B. - 2002. - Vol. 65, Is. 2. - Ст. 24207, DOI 10.1103/PhysRevB.65.024207. - Cited References: 24 . - ISSN 1098-0121
РУБ Physics, Condensed Matter

Аннотация: To describe a partially randomized multilayer structure with arbitrary thicknesses of the interfaces between layers, we introduce a model in which the dependence of a material parameter along the axis of such a Superlattice is described by a Jacobian elliptic sine function with a random spatial modulation of its period. Both one- and three-dimensional inhomogeneities of the period are considered. We develop the correlation function for this model, and investigate the dispersion law and damping of averaged waves in this superlattice. The dependencies of the widths of the gaps in the spectrum and the damping at the boundaries of all odd Brillouin zones, on the thicknesses of the interfaces, and on the dimensionality, intensity, and correlation wave number of the inhomogeneities are found. It is shown that experimental investigations of the widths of the gaps and damping for several Brillouin zones could permit, in principle, determining all parameters of the superlattice as well as the parameters of the inhomogeneities from these spectral characteristics.

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Держатели документа:
LV Kirenskii Inst Phys, Krasnoyarsk 660036, Russia
Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA
ИФ СО РАН

Доп.точки доступа:
Mankov, Y. I.; Maradudin, A. A.; Игнатченко, Вальтер Алексеевич

    Formation of a magnetic soliton lattice in copper metaborate
/ B. . Roessli [et al.] // Phys. Rev. Lett. - 2001. - Vol. 86, Is. 9. - P. 1885-1888, DOI 10.1103/PhysRevLett.86.1885. - Cited References: 26 . - ISSN 0031-9007
РУБ Physics, Multidisciplinary

Аннотация: The magnetic ground state of CuB2O4 is incommensurate at T = 1.8 K and undergoes a continuous phase transition to a noncollinear commensurate antiferromagnetic state at T* similar to 10 K. Close to T* higher-order magnetic satellites are observed. Coexistence of long- and short-range magnetic order is observed in both magnetic phases. This suggests that the association of the Dzyaloshinskii-Moriya interaction and anisotropy leads to the formation of a magnetic soliton lattice.

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Держатели документа:
ETH Zurich, Neutron Scattering Lab, CH-5232 Villigen, Switzerland
Paul Scherrer Inst, CH-5232 Villigen, Switzerland
SB RAS, Inst Phys, Krasnoyarsk 660036, Russia
Inst Max Von Laue Paul Langevin, F-38042 Grenoble 9, France
ИФ СО РАН
Laboratory for Neutron Scattering, ETH Zurich, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
Institute of Physics SB RAS, 660036 Krasnoyarsk, Russian Federation
Institut Laue-Langevin, Avenue des Martyrs, 38042 Grenoble, Cedex 9, France
Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland

Доп.точки доступа:
Roessli, B.; Schefer, J.; Petrakovskii, G. A.; Петраковский, Герман Антонович; Ouladdiaf, B.; Boehm, M.; Staub, U.; Vorotinov, A. M.; Bezmaternikh, L. N.

    The spectrum and damping of waves in partially randomized multilayers
/ V. A. Ignatchenko, Y. I. Mankov, A. A. Maradudin // J. Phys.: Condens. Matter. - 1999. - Vol. 11, Is. 13. - P. 2773-2790, DOI 10.1088/0953-8984/11/13/013. - Cited References: 24 . - ISSN 0953-8984
РУБ Physics, Condensed Matter

Аннотация: The spectrum and damping of waves in partially randomized multilayer structures are calculated. A method of calculation that was proposed and demonstrated earlier, for the model of a superlattice with a harmonic dependence of its material parameters along its axis in the initial state, is extended to the case of a multilayer structure (i.e., a superlattice with sharp interfaces). One- and three-dimensional random modulations of the period are considered, and the correlation function of the superlattice is derived as a series in which each term is a product of a harmonic and a monotonically decaying function. The law of decay of the correlation function is Gaussian for smooth inhomogeneities, and has different forms for one- and three-dimensional short-wavelength inhomogeneities. The spectrum and damping of waves in the superlattice described by this correlation function are found in the weak-coupling approximation in the vicinities of all of the odd Brillouin zone boundaries. Analytical dependences of the main characteristics of the spectrum and damping on the zone number n are obtained. The conditions for the closing of the gaps at the Brillouin zone boundaries are derived, and depend on the dimensionality of the inhomogeneities and the degree of their smoothness.

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Держатели документа:
LV Kirenskii Inst Phys, Krasnoyarsk 660036, Russia
Univ Calif Irvine, Irvine, CA 92697 USA
ИФ СО РАН
L V Kirensky Institute of Physics, 660036 Krasnoyarsk, Russian Federation
University of California, Irvine, CA 92697 4575, United States

Доп.точки доступа:
Mankov, Y. I.; Maradudin, A. A.; Игнатченко, Вальтер Алексеевич

    Effects of cross correlations between 1D and 3D inhomogeneities on the high-frequency susceptibility of superlattices
/ V. A. Ignatchenko, Y. I. Mankov // J. Exp. Theor. Phys. - 2006. - Vol. 102, Is. 4. - P. 625-635, DOI 10.1134/S106377610604011X. - Cited References: 29 . - ISSN 1063-7761
РУБ Physics, Multidisciplinary

Аннотация: Cross Correlations between components of a mixture of one-dimensional (I D) and three-diniensional (3D) inhomogenetics are described by introducing a distribution function taking into account correlations between absolute values of two random variables in the absence of correlations between the variables themselves. This distribution function is used for derivation and analysis of the superlattice correlation function containing a mixture of cross-correlated 1D and 3D in homogeneitics. The effect of such inhomogeneities on the high-frequency susceptibility at the edge of the first Brillouin zone of the superlattice is investigated. It is shown that positive cross correlations partly suppress the effect of a mixture of 1D and 3D inhomogeneities on the wave spectrum: the gap at the boundary of the Brillouin zone increases, and wave damping decreases as compared to the effect produced by a mixture of 1D and 3D inhomogeneities in the absence of cross correlations. Negative cross correlations lead to the opposite effect: the gap decreases and wave damping increases. Cross correlations also lead to the emergence of new resonance effects: a narrow dip or a narrow peak at the center of the band gap (depending on the sign of the correlation factor).

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Держатели документа:
Russian Acad Sci, Kirenskii Inst Phys, Siberian Div, Krasnoyarsk 660036, Russia
ИФ СО РАН
Kirenskii Institute of Physics, Siberian Division, Russian Academy of Sciences, Akademgorodok, Krasnoyarsk, 660036, Russian Federation

Доп.точки доступа:
Mankov, Y. I.; Игнатченко, Вальтер Алексеевич

    Phonon spectroscopy of inhomogeneities in disordered solids
/ L. I. Deich, V. A. Ignatchenko // Solid State Commun. - 1991. - Vol. 80, Is. 10. - P. 881-884, DOI 10.1016/0038-1098(91)90525-Z. - Cited References: 15 . - ISSN 0038-1098
РУБ Physics, Condensed Matter

Аннотация: A possibility to use elastic waves for investigation of inhomogeneities corresponding in size to intermediate order in disordered solids is considered. It is shown that frequency dependencies of phase and group velocities of the elastic waves have some peculiarities which give the possibilities to find the characteristic size of inhomogenities and to determine the parameter of a matter whose fluctuations are most significant for the phenomena under study.

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Держатели документа:
Kirensky Institute of Physics, Krasnoyarsk, 660036, Russian Federation
ИФ СО РАН

Доп.точки доступа:
Ignatchenko, V. A.; Игнатченко, Вальтер Алексеевич; Дейч, Лев Исаакович

    The effect of correlation-properties of inhomogeneities on plasma excitations in a metal
/ V. A. Ignatchenko, Yu. I. Mankov // J. Phys.: Condens. Matter. - 1991. - Vol. 3, Is. 31. - P. 5837-5845, DOI 10.1088/0953-8984/3/31/007. - Cited References: 21 . - ISSN 0953-8984
РУБ Physics, Condensed Matter

Аннотация: We theoretically investigate the manifestations of the non-monotonic character and anisotropic peculiarities of the correlation functions of the inhomogeneities in the dispersion law and damping of plasma waves. The following specific effects have been found: a change in the character of the modifications, dispersion law and damping for small wavenumbers; dependence of the plasma frequency shift on the direction of the wave propagation. We substantiate possibilities for developing the correlation spectroscopy of plasma waves which would enable us not only to measure a correlation radius of the inhomogeneities (this has been suggested earlier), but also to obtain information in the form of the correlation function.

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Держатели документа:
Kirensky Inst. of Phys., Krasnoyarsk, Russian Federation

Доп.точки доступа:
Mankov, Yu. I.; Маньков, Юрий Иннокентьевич; Игнатченко, Вальтер Алексеевич

    The incommensurate magnetic structure of a tetragonal antiferromagnet with antisymmetric exchange
/ S. N. Martynov // J. Exp. Theor. Phys. - 2009. - Vol. 109, Is. 6. - P. 979-988, DOI 10.1134/S1063776109120097. - Cited References: 34 . - ISSN 1063-7761
РУБ Physics, Multidisciplinary
Рубрики:
FLUCTUATION-INDUCED PHASE
   FIELD-INDUCED GAP

   COPPER METABORATE

   WEAK FERROMAGNETISM

   SOLITON LATTICE

   SPIN-WAVES

   CUB2O4

   BA2CUGE2O7

   CSCUCL3

   CHAINS

Кл.слова (ненормированные):
Anti-symmetric -- Antiferromagnetic sublattices -- Antiferromagnets -- Antisymmetric exchange -- Exchange bonds -- Ferromagnetic component -- Ferromagnetic moments -- Ginzburg-Landau functional -- Incommensurate magnetic structures -- Mean field approximation -- Modulation vectors -- Polarization planes -- Polarization vectors -- Symmetry groups -- Antiferromagnetic materials -- Antiferromagnetism -- Crystal orientation -- Crystal symmetry -- Ferromagnetic materials -- Ferromagnetism -- Magnetic devices -- Magnetic structure -- Modulation -- Polarization -- Vector spaces -- Vectors -- Crystallography

Аннотация: Analysis of the incommensurate magnetic structure that emerges for two coexisting types of the antisymmetric Dzyaloshinski-Moriya exchange interaction (the weakly ferromagnetic component of vector D along the tetragonal axis and the helicoidal component distributed in the tetragonal plane) is carried out for the first time for a tetragonal antiferromagnet. The helicoidal component for each pair of interacting spins has a 2D distribution; its direction in the tetragonal plane depends on the direction of the exchange bond in each pair. The Lifshits invariant of the Ginzburg-Landau functional is obtained, which is responsible for the formation of an incommensurate magnetic structure for such a distribution. It is shown in the mean field approximation that the incommensurate magnetic structure that forms in this case is a nonlinear double helicoid with a modulation vector lying in the tetragonal plane and with a varying angle between the polarization planes of quasi-antiferromagnetic sublattices. The ground state of the magnet is degenerate in the orientation of the modulation vector in the tetragonal plane. The rate of variation in the orientations of moments in the polarization planes passing through the tetragonal axis is controlled by the angle between the directions of the moments and the tetragonal axis. The local weakly ferromagnetic moment remaining in the polarization plane varies in magnitude and sign. The relation between the orientations of the modulation and polarization vectors is derived for the cases of simple and inversion tetragonal axes in the space symmetry group of the crystal.

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Держатели документа:
Russian Acad Sci, Kirenskii Inst Phys, Siberian Branch, Krasnoyarsk 660036, Russia
ИФ СО РАН
Kirenskii Institute of Physics, Siberian Branch, Russian Academy of Sciences, Krasnoyarsk, 660036, Russian Federation

Доп.точки доступа:
Мартынов, Сергей Николаевич

    Antisymmetric Exchange in the CuB2O4 A Subsystem
/ S. N. Martynov // JETP Letters. - 2009. - Vol. 90, Is. 1. - P. 55-58, DOI 10.1134/S0021364009130116. - Cited References: 31 . - ISSN 0021-3640
РУБ Physics, Multidisciplinary

Аннотация: The space distribution of the components of the microscopic Hamiltonian of the antisymmetric Dzyaloshinskii-Moriya exchange with respect to the exchange bond pairs of the A subsystem of Cu2+ ions in the crystallographic 4b positions of CuB2O4 has been obtained using symmetry analysis. The possibility of the coexistence of two different types of the exchange spatial distribution is demonstrated. The component of the anti-symmetric exchange vector D parallel to the tetragonal axis has a weakly ferromagnetic distribution for all of the directions of the bonds between the nearest magnetic neighbors. Each exchange bond has an additional component of the antisymmetric exchange parallel to the bond projection on the tetragonal plane. The spatial distribution of these components is helicoidal with the modulation vector in the tetragonal crystal plane.

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Держатели документа:
Russian Acad Sci, Kirensky Inst Phys, Siberian Branch, Krasnoyarsk 660036, Russia
ИФ СО РАН
Kirensky Institute of Physics, Siberian Branch, Russian Academy of Sciences, Krasnoyarsk 660036, Russian Federation

Доп.точки доступа:
Мартынов, Сергей Николаевич

    Magnetoelastic resonance in random-nonhomogeneous ferromagnetics with zero medium magnetostriction
/ L. I. Deich, V. A. Ignatchenko // Zhurnal Eksperimentalnoi Teor. Fiz. - 1995. - Vol. 107, Is. 3. - P. 842-854. - Cited References: 14 . - ISSN 0044-4510
РУБ Physics, Multidisciplinary


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Доп.точки доступа:
Ignatchenko, V. A.; Игнатченко, Вальтер Алексеевич; Дейч, Лев Исаакович

    Effect of spatial fluctuations of the magnetization modulus on the properties of amorphous ferromagnets
/ L. I. Deich, V. A. Ignatchenko // Zhurnal Eksperimentalnoi Teor. Fiz. - 1991. - Vol. 99, Is. 3. - P. 816-830. - Cited References: 27 . - ISSN 0044-4510
РУБ Physics, Multidisciplinary

Аннотация: A model of amorphous ferromagnets with longwave spatial fluctuations of the magnetization modulus M is studied. It is shown that for a correct understanding of the properties of the model, it is principally necessary to take into account the magnetic dipole interaction. This interaction enhances the contribution of the fluctuations of M to the ground state, dispersion law and spin wave attenuation. The spectral and correlation properties of the inhomogeneous ground state and the law of approach of the magnetization to saturation in the model are studied. The dispersion law and spin wave attenuation are investigated. A novel mechanism of formation of a correction of the form T5/2 to the Bloch law in the low temperature dependence of the magnetization is proposed.

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Доп.точки доступа:
Ignatchenko, V. A.; Игнатченко, Вальтер Алексеевич; Дейч, Лев Исаакович

    Partial restoration of the wave spectrum of a superlattice due to cross correlations between one- and three-dimensional inhomogeneities
/ V. A. Ignatchenko, Y. I. Mankov // Phys. Rev. B. - 2007. - Vol. 75, Is. 23. - Ст. 235422, DOI 10.1103/PhysRevB.75.235422. - Cited References: 32 . - ISSN 1098-0121
РУБ Physics, Condensed Matter

Аннотация: Effects of cross correlations between one-dimensional (1D) and three-dimensional (3D) random inhomogeneities on the wave spectrum in sinusoidal superlattices are studied theoretically. The situation when the gap in the spectrum (the forbidden zone) at the first Brillouin zone boundary of the superlattice is closed under the action of the 1D inhomogeneities is considered. The phenomenon of the partial opening of this gap is found when the 3D inhomogeneities cross correlated with the 1D inhomogeneities add to the superlattice. The appearance of the logarithmic resonance in the center of the forbidden zone under the action of the cross correlations is shown. The physical nature of the effects in the wave spectrum of the superlattice that are caused by the cross correlations and the relation of these effects with the asymptotic properties of the correlation function of inhomogeneities are discussed.

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Держатели документа:
SB RAS, LV Kirensky Inst Phys, Krasnoyarsk 660036, Russia
ИФ СО РАН
L. V. Kirensky Institute of Physics, SB RAS, 660036 Krasnoyarsk, Russian Federation

Доп.точки доступа:
Mankov, Y. I.; Игнатченко, Вальтер Алексеевич