Главная
Авторизация
Фамилия
Пароль
 

Базы данных


Труды сотрудников ИФ СО РАН - результаты поиска

Вид поиска

Область поиска
Формат представления найденных документов:
полный информационныйкраткий
Отсортировать найденные документы по:
авторузаглавиюгоду изданиятипу документа
Поисковый запрос: (<.>S=LATTICE-DYNAMICS<.>)
Общее количество найденных документов : 10
Показаны документы с 1 по 10
1.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Krylov A. S., Goryainov S. V., Vtyurin A. N., Krylova S. N., Sofronova S. N., Laptash N. M., Emelina T. B., Voronov V. N., Babushkin S. V.
Заглавие : Raman scattering study of temperature and hydrostatic pressure phase transitions in Rb2KTiOF5 crystal
Место публикации : J. Raman Spectrosc.: Wiley-Blackwell, 2012. - Vol. 43, Is. 4. - P.577-582. - ISSN 0377-0486, DOI 10.1002/jrs.3071
Примечания : Cited References: 24. - This work was partly supported by integration project SB RAS No 101, Russian Foundation for Basic Research project No 11-02-98002-r_siberia, No 09-02-00062, SS-4645.2010.2.
Предметные рубрики: LATTICE-DYNAMICS
OXYFLUORIDES
(NH4)(3)TIOF5
SPECTRA
ELPASOLITE
Ключевые слова (''Своб.индексиров.''): structural phase transition--rb2ktiof5--raman spectroscopy--hysteresis--hydrostatic pressure
Аннотация: Raman spectra of Rb2KTiOF5 crystal were obtained and analyzed in the temperature range from 77 to 297 K and under hydrostatic pressure up to 4.2 GPa (at T = 295 K). The experimental results were compared with quantum-chemical simulation of TiOF5 pseudo-octahedron. To interpret effects of lattice ordering, phonon spectra of several ordered phases of Rb2KTiOF5 were calculated within ab initio generalized Gordon–Kim model, and ordering of TiOF5 molecular groups were simulated within Monte Carlo approach. The spectra exhibited orientation disordering in the cubic phase under ambient conditions. Cooling below the phase transition temperature (215 K) leads to partial ordering of the structure. The isotropic perovskite-like phase was found to undergo first-order transition into a low-symmetry anisotropic phase at about 1 GPa. Further compression up to 4.1 GPa did not show any effects associated with phase transitions. Copyright © 2011 John Wiley & Sons, Ltd.
Смотреть статью,
Scopus,
WoS,
Читать в сети ИФ
Найти похожие
2.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Vtyurin A. N., Krylov A. S., Goryainov S. V., Krylova S. N., Oreshonkov A. S., Voronov V. N.
Заглавие : A raman study of hydrostatic pressure induced phase transitions in Rb2KInF6 crystals
Место публикации : Phys. Solid State: MAIK Nauka-Interperiodica / Springer, 2012. - Vol. 54, Is. 5. - P.934-936. - ISSN 1063-7834, DOI 10.1134/S1063783412050472
Примечания : Cited References: 16. - This study was supported by the Russian Foundation for Basic Research (project nos. 11-02-98002-r_sibir' and 09-02-00062), the Siberian Branch of the Russian Academy of Sciences (integration project no. 101), and the Council on Grants from the President of the Russian Federation (grant no. HSh-4645.2010.2).
Предметные рубрики: LATTICE-DYNAMICS
ELPASOLITES
SPECTRA
Аннотация: The Raman spectra of the elpasolite (Rb2KInF6) crystal have been studied in the pressure range from 0 to 5.3 GPa at a temperature of 295 K. A phase transition at a pressure of approximately 0.9 GPa has been found. An analysis of the variations in the spectral parameters has led to the conclusion that the phase transition to a distorted phase is accompanied by the doubling of the volume of the primitive cell of the initial cubic phase. Numerical calculations of the lattice dynamics in the Rb2KInF6 crystal have been performed. The numerical simulation has established that the phase transition at a pressure of 0.9 GPa is associated with condensation of the F (lg) mode. A probable high-pressure phase is the phase with space group C2/m.
Смотреть статью,
Scopus,
WoS,
Читать в сети ИФ
Найти похожие
3.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Krylov A. S., Sofronova S. N., Kolesnikova E. M., Ivanov Y. N., Sukhovsky A. A., Goryainov S. V., Ivanenko A. A., Shestakov N. P., Kocharova A. G., Vtyurin A. N.
Заглавие : Experimental and theoretical methods to study structural phase transition mechanisms in K3WO3F3 oxyfluoride
Коллективы : Russian Foundation for Basic Research [4828.2012.2, 12-02-31205]; Federal Special Program "Scientific and scientific-pedagogical staff of innovative Russia" [8379]
Место публикации : J. Solid State Chem. - 2014. - Vol. 218. - P.32-37. - ISSN 0022-4596, DOI 10.1016/j.jssc.2014.05.028. - ISSN 1095-726X
Примечания : Cited References: 21. - The Authors are grateful to Prof. Zinenko V.I. for constructive discussion of the results. The work has been done with financial support of the Russian Foundation for Basic Research projects nos. 4828.2012.2, 12-02-31205; Federal Special Program "Scientific and scientific-pedagogical staff of innovative Russia" project no. 8379.
Предметные рубрики: LATTICE-DYNAMICS
RAMAN-SCATTERING
ELPASOLITE
(NH4)3WO3F3
SPECTROSCOPY
CRYSTALS
Ключевые слова (''Своб.индексиров.''): raman spectroscopy--ir spectroscopy--nmr spectroscopy--high hydrostatic pressure--oxyfluorides--lattice dynamics calculations
Аннотация: The results of structural phase transitions mechanisms study in K3WO3F3oxyfluoride are represented by different experimental and theoretical methods. The structural phase transition anomalies at T1=452 K and T2=414 K of Raman and IR spectra have been analyzed. Using vibrational spectroscopy methods, the NMR-experiment has been done to clarify the nature of found phase transitions: displacive types or order-disorder types. The model of “disordered” crystal was proposed, and the results of lattice dynamics calculation in frameworks of the generalized Gordon–Kim method of ordered (R3) and “disordered” crystals were compared. The high pressure phases were studied by the Raman technique too.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
4.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Aleksandrov K. S., Voronov V. N., Vtyurin A. N., Krylov A. S., Molokeev M. S., Pavlovskii M. S., Goryainov S. V., Likhacheva A. Y., Ancharov A. I.
Заглавие : Pressure-induced phase transition in the cubic ScF3 crystal
Коллективы : Russian Academy of Sciences (Siberian Branch)
Место публикации : Phys. Solid State. - 2009. - Vol. 51, Is. 4. - P.810-816. - ISSN 1063-7834, DOI 10.1134/S1063783409040295
Примечания : Cited References: 22. - The authors are grateful to V.I. Zinenko for helpful discussion of the results.This work was conducted in the framework of Integration Project (no. 3.7) of the Russian Academy of Sciences (Siberian Branch).
Предметные рубрики: RAMAN-SPECTROSCOPY
POWDER DIFFRACTION
LATTICE-DYNAMICS
SCATTERING
Аннотация: Pressure-induced phase transitions in the ScF3 crystal were studied using synchrotron radiation diffraction, polarization microscopy, and Raman spectroscopy. The phase existing in the range 0.6-3.0 GPa is optically anisotropic; its structure is described by space group R (3) c (Z = 2), and the transition is due to rotation of ScF6 octahedra around a threefold axis. The pressure dependence of the structural parameters and angle of rotation are determined. The number of Raman spectral lines corresponds to that expected for this structure; above the phase transition point, a recovery of soft modes takes place. At a pressure of 3.0 GPa, a transition occurs to a new phase, which remains metastable as the pressure decreases. The results are interpreted using an ab initio method based on the Gordon-Kim approach.
WOS,
Читать в сети ИФ
Найти похожие
5.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Shneyder E. I., Spitaler J., Kokorina E. E., Nekrasov I. A., Gavrichkov V. A., Draxl C., Ovchinnikov S. G.
Заглавие : Coupling of Hubbard fermions with phonons in La2 CuO4: A combined study using density-functional theory and the generalized tight-binding method
Место публикации : J. Alloys Compd.: Elsevier, 2015. - Vol. 648. - P.258-264. - ISSN 0925-8388, DOI 10.1016/j.jallcom.2015.05.150
Примечания : Cited References: 60. - We acknowledge the stimulating discussions with V.V. Val'kov, D.M. Dzebisashvilly, M.M. Korshunov and I.S. Sandalov. E.I.S. and S.G.O. are thankful to the Russian Science Foundation (project No. 14-12-00061) for the support of the research given in Sections 2, 6 and 7. E.E.K. and I.A.N. are thankful to the State Contract No. 0389-2014-0001 and RFBR grant No. 14-02-00065 for the support of the research given in Section 5. Financial support of the research given in Sections 3 and 4 by the Austrian Federal Government (in particular from Bundesministerium fur Verkehr, Innovation und Technologie and Bundesministerium fur Wissenschaft, Forschung und Wirtschaft) represented by Osterreichische Forschungsforderungsgesellschaft mbH and the Styrian and the Tyrolean Provincial Government, represented by Steirische Wirtschaftsforderungsgesellschaft mbH and Standortagentur Tirol, within the framework of the COMET Funding Programme is gratefully acknowledged by C.D. and J.S.
Предметные рубрики: MEAN-FIELD THEORY
LINEAR-RESPONSE THEORY
CUPRATE SUPERCONDUCTORS
ELECTRONIC-STRUCTURE
CORRELATED SYSTEMS
LATTICE-DYNAMICS
BAND-STRUCTURE
LA2CUO4
MODEL
LA2-XSRXCUO4
Ключевые слова (''Своб.индексиров.''): high-temperature superconductivity--electron-phonon coupling--density-functional theory--generalized tight-binding approach
Аннотация: We present results for the electron-phonon interaction of the Γ-point phonons in the tetragonal high-temperature phase of La2 CuO4 obtained from a hybrid scheme, combining density-functional theory (DFT) with the generalized tight-binding approach. As a starting point, eigenfrequencies and eigenvectors for the Γ-point phonons are determined from DFT within the frozen phonon approach utilizing the augmented plane wave + local orbitals method. The so obtained characteristics of electron-phonon coupling are converted into parameters of the generalized tight-binding method. This approach is a version of cluster perturbation theory and takes the strong on-site electron correlations into account. The obtained parameters describe the interaction of phonons with Hubbard fermions which form quasiparticle bands in strongly correlated electron systems. As a result, it is found that the Γ-point phonons with the strongest electron-phonon interaction are the A2u modes (236 cm-1, 131 cm-1 and 476 cm-1). Finally it is shown, that the single-electron spectral-weight redistribution between different Hubbard fermion quasiparticles results in a suppression of electron-phonon interaction which is strongest for the triplet Hubbard band with z oriented copper and oxygen electrons. © 2015 Elsevier B.V. All rights reserved.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
6.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Krylov A. S., Krylova S. N., Vtyurin A. N., Voronov V. N., Oreshonkov A. S.
Заглавие : Raman Scattering Study Temperature Phase Transitions of Rb2KInF6 Crystal
Место публикации : Ferroelectrics: TAYLOR & FRANCIS LTD, 2011. - Vol. 416. - P95-100. - ISSN 0015-0193, DOI 10.1080/00150193.2011.577713
Примечания : Cited References: 9. - Authors wish to thank prof. K. S. Aleksandrov and prof. I. N. Flerov for their valuable support and useful discussions. This work has been financially supported by grants RFFBR 08-02-00066, 09-02-00062, SS-1011.2008.2.
Предметные рубрики: LIGHT-SCATTERING
LATTICE-DYNAMICS
OPTICAL PHONONS
ELPASOLITE
RB2KSCF6
Ключевые слова (''Своб.индексиров.''): rb2kinf6--temperature phase transitions--raman scattering--lattice dynamics
Аннотация: Raman scattering spectra of Rb2KInF6 crystal have been studied in a wide temperature range, including two phase transitions: from cubic to tetragonal, and then - to the monoclinic phase. Hardening of soft phonon modes was observed that attributes them to the transitions of displacive type. Parameters of Raman lines have been quantitatively analyzed and found in good agreement with known thermodynamic characteristics of these transitions. No evidences of order - disorder processes were observed in the Raman spectra of the high-symmetry phase.
WOS,
Читать в сети ИФ
Найти похожие
7.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Maksimov E. G., Zinenko V. I., Zamkova N. G.
Заглавие : Ab initio calculations of the physical properties of ionic crystals
Место публикации : Phys. Usp.: TURPION LTD, 2004. - Vol. 47, Is. 11. - P1075-1099. - ISSN 1063-7869, DOI 10.1070/PU2004v047n11ABEH001796
Примечания : Cited References: 90
Предметные рубрики: STRUCTURAL PHASE-TRANSITION
LOCAL-FIELD CORRECTIONS
INDUCED BREATHING MODEL
ZINC-BLENDE STRUCTURE
ELECTRON-GAS THEORY
LATTICE-DYNAMICS
MICROSCOPIC CALCULATIONS
MACROSCOPIC POLARIZATION
STATISTICAL-MECHANICS
1ST-PRINCIPLES THEORY
Аннотация: First-principles calculations of the physical properties of ionic crystals are reviewed. Two markedly different approaches within the framework of the density functional theory are described. In one of them, the electron spectrum and wave functions are treated within the standard band picture based on the solution of Kohn-Sham equations. In the second approach, the total electron density of a crystal is represented as a super-position of the densities of individual ions. The problem of determining the electric polarization of a crystal is discussed for each approach. It is shown that it is the use of Bloch functions rather than the physics of the phenomenon that complicates the solution of this problem within the Kohn-Sham framework. The deformable and polarizable ion model is described in detail, and its application to calculating many properties of ionic crystals, including the lattice dynamics and structural stability of crystal phases, is discussed.
WOS,
Scopus
Найти похожие
8.

Вид документа : Статья из сборника (однотомник)
Шифр издания :
Автор(ы) : Vtyurin A. N., Isaenko L. I., Krylova S. N., Yelisseyev A., Shebanin A. P., Turchin P. P., Zamkova N. G., Zinenko V. I.
Заглавие : Raman spectra and elastic properties of KPb2Cl5 crystals
Место публикации : 11th International Conference on Phonon Scattering in Condensed Matter (PHONONS 2004) (JUL 25-30, 2004, St Petersburg, RUSSIA): WILEY-V C H VERLAG GMBH, 2004. - P3142-3145. - ISBN 3-527-40588-7, DOI 10.1002/pssc.200405401
Примечания : Cited References: 10
Предметные рубрики: LATTICE-DYNAMICS
Ключевые слова (''Своб.индексиров.''): computer simulation--crystal structure--eigenvalues and eigenfunctions--halogen compounds--nonlinear optics--phonons--potassium compounds--vectors--elastic constants--heavy cations--ionic electron envelopes--ionic interactions--raman scattering
Аннотация: Raman scattering spectra and elastic constants of KPb2Cl5 crystals have been studied. The results obtained are interpreted in terms of the ab initio lattice dynamics model taking into account multipole moments of ionic electron envelopes. The experimental results have been found to be in good agreement with numerical simulation; the narrow phonon spectra are shown to be due to a considerable contribution of heavy cations into the eigenvectors of the higher frequency lattice modes.
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
9.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Zinenko V. I., Zamkova N. G.
Заглавие : Theory of an Fm3m - I4/m structural phase transition in an Rb2KScF6 crystal
Разночтения заглавия :us: Theory of an Fm3mI4/m Structural Phase Transition in an Rb2KScF6 Crystal
Место публикации : J. Exp. Theor. Phys.: AMER INST PHYSICS, 2000. - Vol. 91, Is. 2. - P314-323. - ISSN 1063-7761, DOI 10.1134/1.1311990
Примечания : Cited References: 16
Предметные рубрики: FIRST-PRINCIPLES THEORY
LATTICE-DYNAMICS
PEROVSKITES
ELPASOLITES
Аннотация: An Rb2KScF6 crystal having an elpasolite structure undergoes a sequence of Fm3m -- I4/m -- P12(1)/n1 structural phase transitions where the transition to the tetragonal phase is associated with "rotation" of the ScF6 octahedron. An effective Hamiltonian is constructed to describe the Fm3m -- I4/m transition using the approximation of a local mode for which we selected a "soft mode" whose eigenvector corresponds to the rotation of the octahedron. The effective Hamiltonian also includes the relationship between the local mode and the homogeneous elastic strains. The parameters of the effective Hamiltonian were determined using the generalized Gordon-Kim model of an ionic crystal which allows for the deformability and polarizability of the ions. The thermodynamic properties of a system with this model Hamiltonian were investigated using the Monte Carlo method. The calculated phase transition temperature of 250 K is almost the same as the experimental value (252 K). The tetragonal phase remains stable as far as T = 0 K and a second transition (to the monoclinic phase) cannot be obtained using this effective Hamiltonian. This suggests that if the transition to the tetragonal phase is mainly associated with "rotations" of the octahedrons, in order to describe the phase transition to the monoclinic phase the effective Hamiltonian must allow for additional degrees of freedom mainly associated with the motion of rubidium ions. (C) 2000 MAIK "Nauka/Interperiodica".
WOS,
Scopus,
Читать в сети ИФ
Найти похожие
10.

Вид документа : Статья из журнала
Шифр издания :
Автор(ы) : Krylov A. S., Molokeev M. S., Misyul S. V., Krylova S. N., Oreshonkov A. S., Ivanenko A. A., Zykova V. A., Ivanov Y. N., Sukhovsky A. A., Voronov V. N., Safonov I. N., Vtyurin A. N.
Заглавие : Crystal structure and phase transitions of a layered perovskite-like CsScF4 crystal
Коллективы : Russian Foundation for Basic Research [16-02-00102]
Место публикации : CrystEngComm: Royal Society of Chemistry, 2016. - Vol. 18, Is. 43. - P.8472-8486. - ISSN 1466-8033, DOI 10.1039/c6ce01144f
Примечания : Cited References:47. - The authors are grateful to Prof. I. N. Flerov for valuable support and useful discussions. This work was partly supported by the Russian Foundation for Basic Research, Project 16-02-00102. The research is partially conducted within the framework of the state task of the Ministry of Education and Science of the Russian Federation for Siberian Federal University on R&D performance in 2014 (Task 3.2534.2014/K). X-ray data from powders, Raman NMR, and IR spectra were obtained with use the analytical equipment of Krasnoyarsk Center of collective use SB RAS.
Предметные рубрики: NEGATIVE THERMAL-EXPANSION
RAMAN-SCATTERING
LATTICE-DYNAMICS
Аннотация: This work is devoted to the complex research on temperature phase transitions in a CsScF4 crystal. The crystal structure was solved and refined at different temperatures by using the Rietveld method. Structural phase transitions were investigated by using the following spectroscopic methods, some of them for the first time: Brillouin spectroscopy, Raman spectroscopy, IR absorption spectroscopy and NMR. The symmetry analysis of the Brillouin zone center of all phases is presented. The vibrational spectra of the crystal in three phases have been calculated. The structural phase transition mechanism was determined. The transitions at T-1 = 475 K and T-2 = 317.5 K are of displacement type. The Raman soft modes have been associated with rotations of the ScF6 octahedral group.
Смотреть статью,
Scopus,
WOS,
Читать в сети ИФ
Найти похожие
 

Другие библиотеки

© Международная Ассоциация пользователей и разработчиков электронных библиотек и новых информационных технологий
(Ассоциация ЭБНИТ)