Главная
Авторизация
Фамилия
Пароль
 

Базы данных


Труды сотрудников ИФ СО РАН - результаты поиска

Вид поиска

Область поиска
в найденном
Формат представления найденных документов:
полныйинформационныйкраткий
Отсортировать найденные документы по:
авторузаглавиюгоду изданиятипу документа
Поисковый запрос: (<.>S=Phase-transition<.>)
Общее количество найденных документов : 28
Показаны документы с 1 по 10
 1-10    11-20   21-28 
1.


    Bondarenko, I. N.
    Magnetic transitions in layered triangular antiferromagnets / I. N. Bondarenko, R. S. Gekht, V. I. Ponomarev // Phys. Lett. A. - 1996. - Vol. 222, Is. 4. - P. 269-274, DOI 10.1016/0375-9601(96)00635-4. - Cited References: 22 . - ISSN 0375-9601
РУБ Physics, Multidisciplinary
Рубрики:
HEISENBERG-ANTIFERROMAGNET
   PHASE-TRANSITION

   VBR2

   SYSTEMS

   FIELD

   VCL2

Кл.слова (ненормированные):
triangular antiferromagnets -- quantum and thermal fluctuations -- successive phase transitions -- Quantum and thermal fluctuations -- Successive phase transitions -- Triangular antiferromagnets
Аннотация: Magnetic states and phase transitions of the layered triangular antiferromagnets in an applied field are studied. It is shown that in compounds like VBr2 and VCl2 quantum effects change the ground state structure and cause successive phase transitions as the magnetic field increases. Coplanar structures of different spin configuration are realized far from the saturation field and a noncoplanar structure of umbrella-type configuration is realized near this field. The ground-state phase diagram is constructed, and a finite region of fields where the collinear phase is also possible is indicated.

WOS,
Scopus
Держатели документа:
Kirensky Institute of Physics, Russian Academy of Sciences, Siberian Branch, Krasnoyarsk 660036, Russian Federation

Доп.точки доступа:
Gekht, R. S.; Ponomarev, V. I.
}
Найти похожие
2.


    Averyanov, E. M.
    Orientation ordering and critical behavior of discoid nematics / E. M. Averyanov // Zhurnal Eksperimentalnoi Teor. Fiz. - 1996. - Vol. 110, Is. 5. - P. 1820-1840. - Cited References: 55 . - ISSN 0044-4510
РУБ Physics, Multidisciplinary
Рубрики:
LIQUID-CRYSTALS
   PHASE-TRANSITION

   ISOTROPIC-PHASE

   LOCAL FIELD

   SMECTIC-A

   MOLECULES

   SUSCEPTIBILITY

   CONFORMATION

   PARAMETER

   DYNAMICS


WOS
}
Найти похожие
3.


    Avramov, P. V.
    Atomic-core dynamics and the electronic structure of some endo- and exohedral complexes of fullerenes with light elements / P. V. Avramov, S. A. Varganov, S. G. Ovchinnikov // Phys. Solid State. - 2000. - Vol. 42, Is. 11. - P. 2168-2175, DOI 10.1134/1.1324059. - Cited References: 39 . - ISSN 1063-7834
РУБ Physics, Condensed Matter
Рубрики:
M-AT-C-60 ENDOHEDRAL COMPLEXES
   MOLECULAR-DYNAMICS

   PHASE-TRANSITION

   AB-INITIO

   SOLID C60

   C-60

   IONS

Аннотация: The atomic and electronic structure of some endo-, exo-, and endo-exohedral complexes of the fullerene C-60 with various guest atoms and molecules (He-n, H-2, and Li-2) are investigated using semiempirical and nonempirical quantum-chemical methods. The atomic core dynamics is studied by the method of molecular dynamics. It is shown that guest atoms and molecules in fullerene polyhedra acquire an orbital angular momentum due to the correlated motion of nuclei above the low-energy barriers of the potential surface within the carbon polyhedron even at low temperatures (from 4 to 78 K). The emergence of orbital angular momenta of nuclei of guest atoms and molecules is attributed to a change in the contribution of the orbital angular momentum of electrons to the potential surface of the complexes. The motion of Li ions in a polyhedron leads to blurring of the top of the valence band and to the emergence of a charge polarization wave in the carbon polyhedron. (C) 2000 MAIK "Nauka/Interperiodica".

WOS,
Scopus,
Читать в сети ИФ
Держатели документа:
Russian Acad Sci, Kirenskii Inst Phys, Siberian Div, Krasnoyarsk 660036, Russia
Krasnoyarsk State Univ, Krasnoyarsk, Russia
Krasnoyarsk State Univ, Krasnoyarsk 660062, Russia
ИФ СО РАН

Доп.точки доступа:
Varganov, S. A.; Ovchinnikov, S. G.; Овчинников, Сергей Геннадьевич; Аврамов, Павел Вениаминович
}
Найти похожие
4.


    Ovchinnikov, S. G.
    Many-electron model of band structure and metal-insulator transition under pressure in FeBO3 / S. G. Ovchinnikov // JETP Letters. - 2003. - Vol. 77, Is. 12. - P. 676-679, DOI 10.1134/1.1604419. - Cited References: 20 . - ISSN 0021-3640
РУБ Physics, Multidisciplinary
Рубрики:
PHASE-TRANSITION
   FERROMAGNETISM

   STATE

Аннотация: A many-electron model is proposed for the band structure of FeBO3 with regard to strong electron correlations in the d (4), d (5), and d (6) configurations. Under normal conditions, FeBO3 is characterized by a dielectric charge-transfer gap in the strong correlation regime U W. With increasing pressure, not only does the d-band W width grow but simultaneously the effective Hubbard parameter U-eff sharply drops, which is due to the crossover of high-spin and low-spin ground state terms of the Fe2+, Fe3+, and Fe4+ ions. It is predicted that a transition from the semiconducting antiferromagnetic state to the metallic paramagnetic state will occur in the high-pressure phase with increasing temperature. (C) 2003 MAIK "Nauka / Interperiodica".

WOS,
Scopus,
Читать в сети ИФ
Держатели документа:
Russian Acad Sci, Inst Phys, Siberian Div, Krasnoyarsk 660036, Russia
ИФ СО РАН
Institute of Physics, Siberian Division, Russian Academy of Sciences, Krasnoyarsk 660036, Russian Federation

Доп.точки доступа:
Овчинников, Сергей Геннадьевич
}
Найти похожие
5.


    Aver'yanov, E. M.
    Fluctuations of orientational order in a uniaxial nematic liquid crystal with biaxial molecules and its response to an external field / E. M. Aver'yanov // Phys. Solid State. - 2003. - Vol. 45, Is. 5. - P. 990-1001, DOI 10.1134/1.1575350. - Cited References: 30 . - ISSN 1063-7834
РУБ Physics, Condensed Matter
Рубрики:
PHASE-TRANSITION
   SMECTIC-A

   PARTICLES

   SYSTEM

   LANDAU

   MODEL

Аннотация: Homogeneous thermal fluctuations of the orientational order parameters S and G of biaxial molecules in a uniaxial nematic liquid crystal are investigated in the framework of the molecular-statistical theory. It is demonstrated that the molecular biaxiality significantly affects the order parameters S and G, their temperature dependences in the nematic phase, the amplitude and the temperature dependence of the order parameter fluctuations in the nematic and isotropic phases, and the character of the transition from the nematic phase to the isotropic liquid phase. It is established that the fluctuations of the parameters S and G in the nematic phase are related to the temperature dependences of S and G and the susceptibilities chi(S) and chi(G) of the nematic liquid crystal to external fields, which leads to a change in the parameters S and G at a fixed director orientation. Explanations are offered for the known experimental data on the orientational ordering of biaxial molecules under the action of external fields in the isotropic phase of nematic liquid crystals. (C) 2003 MAIK "Nauka/Interperiodica".

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

Доп.точки доступа:
Аверьянов, Евгений Михайлович
}
Найти похожие
6.


   
    Analysis of the electrical and optical properties of VBO3 single crystals and Fe1-xVxBO3 solid solutions on the basis of a many-electron model of energy band structure / N. B. Ivanova [et al.] // Phys. Solid State. - 2004. - Vol. 46, Is. 8. - P. 1462-1468, DOI 10.1134/1.1788779. - Cited References: 32. - One of the authors (M.M.A.) would like to thank the Deutsche Forschungsgemeinschaft (SFB608) for financial support. This study was supported by the Russian Foundation for Basic Research (project no. 03-02-16286), the program "Integration" (project no. B0017), and the program of the Division of Physical Sciences of the Russian Academy of Sciences "Strongly Correlated Electrons" . - ISSN 1063-7834
РУБ Physics, Condensed Matter
Рубрики:
MAGNETIC-PROPERTIES
   CALCITE STRUCTURE

   PHASE-TRANSITION

   FERRIC BORATE

   HIGH-PRESSURE

   FEBO3

   FE1-XCRXBO3

   FERROMAGNET

   MOSSBAUER

   SPECTRA

Аннотация: A many-electron model of the energy band structure of VBO3 and of Fe1 - xVxBO3 solid solutions is proposed with strong electron correlations taken into account. Experimental optical absorption spectra and data on the resistivity are discussed in the framework of the suggested model. Variation in the magnetic and electronic properties of VBO3 and Fe1 - xVxBO3 under high pressure is predicted. For VBO3, a Mott-Hubbard (insulator-metal) transition is expected in the high-pressure phase. In Fe1 - xVxBO3 solid solutions, a nontrivial variation in the properties is predicted, leading to the appearance of a different magnetic state. (C) 2004 MAIK "Nauka / Interperiodica".

WOS,
Scopus,
РИНЦ,
Смотреть статью,
Читать в сети ИФ

Публикация на русском языке Анализ электрических и оптических свойств монокристаллов VBO[3] и твердых растворов Fe[1-x]V[x]BO[3] на основе многоэлектронной модели из зонной структуры [Текст] / Н. Б. Иванова [и др.] // Физ. тверд. тела. - 2004. - Т. 46 Вып. 8. - С. 1422-1427

Держатели документа:
Krasnoyarsk State Tech Univ, Krasnoyarsk 660074, Russia
Russian Acad Sci, Siberian Div, Kirenskii Inst Phys, Krasnoyarsk 660036, Russia
Univ Cologne, Inst Phys 2, D-50937 Cologne, Germany
ИФ СО РАН
Krasnoyarsk State Tech. University, Krasnoyarsk, 660074, Russian Federation
II. Physikalisches Institut, Universitat zu Koln, Koln, 50937, Germany

Доп.точки доступа:
Ivanova, N. B.; Иванова, Наталья Борисовна; Kazak, N. V.; Казак, Наталья Валерьевна; Markov, V. V.; Марков, Владимир Витальевич; Ovchinnikov, S. G.; Овчинников, Сергей Геннадьевич; Rudenko, V. V.; Руденко, Валерий Васильевич; Abd-Elmeguid, M. M.
}
Найти похожие
7.


    Ovchinnikov, S. G.
    The energy band structure and optical spectra of FeBO3 calculated with allowance for strong electron correlations / S. G. Ovchinnikov, V. N. Zabluda // J. Exp. Theor. Phys. - 2004. - Vol. 98, Is. 1. - P. 135-143, DOI 10.1134/1.1648107. - Cited References: 32. - This study was supported by the Russian Foundation for Basic Research (project no. 03-02-16286) and by the “Strongly Correlated Electrons” Program of the Department of Physical Sciences of the Russian Academy of Sciences . - ISSN 1063-7761
РУБ Physics, Multidisciplinary
Рубрики:
PHASE-TRANSITION
   HIGH-PRESSURE

   FERROMAGNETISM

   MODEL

Кл.слова (ненормированные):
Atomic physics -- Band structure -- Charge transfer -- Excitons -- Green's function -- Light absorption -- Dielectric gap -- Energy band structure -- Lehmann spectral representation -- Optical spectra -- Iron compounds
Аннотация: A model of the energy band structure of iron borate (FeBO3) is proposed that combines a one-electron description of the sp states of boron and oxygen with a many-electron description of the d states of iron. The Green functions of d electrons are calculated using the exact Lehmann spectral representation. The energies of the d-type quasiparticles are calculated using terms of the d(4) , d(5) , and d(6) electron configurations. The optical absorption spectrum of FeBO3 is determined by local excitons and by the electron excitations with charge transfer. The latter excitations control the nature of the dielectric gap in FeBO3 crystals. The model parameters are determined from a comparison to the exciton energies. The density of single-particle states in FeBO3 is calculated. The main bands in the calculated optical absorption spectrum agree well with experimental data for energies up to 3 eV. (C) 2004 MAIK "Nauka/Interperiodica".

WOS,
Scopus,
РИНЦ,
Смотреть статью,
Читать в сети ИФ

Публикация на русском языке Овчинников, Сергей Геннадьевич. Энергетическая структура и оптические спектры FeBO[3] с учетом сильных электронных корреляций [Текст] / С. Г. Овчинников, В. Н. Заблуда // Журн. эксперим. и теор. физ. - 2004. - Т. 125 Вып. 1. - С. 150-159

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

Доп.точки доступа:
Zabluda, V. N.; Заблуда, Владимир Николаевич; Овчинников, Сергей Геннадьевич
}
Найти похожие
8.


   
    Raman spectra and pressure-induced lattice instabilities in RbMnCl3 crystal / A. N. Vtyurin [et al.] // 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. - 11th International Conference on Phonon Scattering in Condensed Matter (PHONONS 2004) (JUL 25-30, 2004, St Petersburg, RUSSIA). - P. 3097-3100, DOI 10.1002/pssc.200405332. - Cited References: 14 . - ISBN 3-527-40588-7
РУБ Physics, Condensed Matter
Рубрики:
PHASE-TRANSITION
   SPECTROSCOPY

Кл.слова (ненормированные):
Frequencies -- Hydrostatic pressure -- Mathematical models -- Parameter estimation -- Raman scattering -- Spectrometers -- Stability -- Ambient conditions -- Anomalies -- Lattice instabilities -- Structural units -- Rubidium compounds
Аннотация: Raman scattering spectra of the RbMnCl3 crystal have been studied under ambient conditions and under high hydrostatic pressure. The results produced have been interpreted with the ab initio model. The experimental data agree well with the estimated values in the low frequency range and show a slightly worse agreement at higher frequencies. A phase transition from the hexagonal phase to the perovskite phase predicted earlier within the same model was observed under high pressure (above 0.7 GPa) and new transitions to lower symmetry phases were found at higher pressures (1.1 GPa and 5 GPa). (C) 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

WOS,
Scopus,
Читать в сети ИФ
Держатели документа:
Kirensky Inst Phys, Krasnoyarsk 660036, Russia
ИФ СО РАН
Kirensky Institute of Physics, 660036 Krasnoyarsk, Russian Federation
Inst. of Mineralogy and Petrography, 630090 Novosibirsk, Russian Federation

Доп.точки доступа:
Vtyurin, A. N.; Втюрин, Александр Николаевич; Goryainov, S. V.; Krylov, A. S.; Крылов, Александр Сергеевич; Krylova, S. N.; Крылова, Светлана Николаевна; Shefer, A. D.; Zamkova, N. G.; Замкова, Наталья Геннадьевна; Zinenko, V. I.; Зиненко, Виктор Иванович
}
Найти похожие
9.


    Gekht, R. S.
    A quantum spin liquid in a two-layer triangular antiferromagnet / R. S. Gekht, I. N. Bondarenko // J. Exp. Theor. Phys. - 2005. - Vol. 101, Is. 5. - P. 868-880, DOI 10.1134/1.2149066. - Cited References: 43 . - ISSN 1063-7761
РУБ Physics, Multidisciplinary
Рубрики:
ONE-DIMENSIONAL ANTIFERROMAGNETS
   DIMER GROUND-STATE

   MEAN-FIELD THEORY

   HEISENBERG-ANTIFERROMAGNET

   SYSTEM SRCU2(BO3)(2)

   PHASE-TRANSITION

   GAP

   FLUCTUATIONS

   EXCITATIONS

   LATTICE

Кл.слова (ненормированные):
Antiferromagnetic materials -- Magnetic fields -- Magnetization -- Phase diagrams -- Spectrum analysis -- Thermodynamics -- Analogous systems -- Square lattices -- Thermodynamic quantities -- Two-layer triangular antiferromagnets -- Quantum theory
Аннотация: The possibility of implementing a quantum-spin-liquid-type state in a two-layer triangular spin-1/2 antiferromagnet at T = 0 is investigated. The ratio of intra- to interlayer exchange constants (j) is found under which a transition from the classical state with 120 degrees triangular order to a quantum state with zero magnetization per site occurs; in this case, the spins of adjacent layers form singlets that are separated from triplet excitations by an energy gap. Compared with an analogous system with the square lattice, the range of j in which the classical ordered state is realized turns out to be an order of magnitude smaller due to the effects of frustration; in this case, the behavior of thermodynamic quantities is analogous, on the whole, to that in two-layer square lattices; a difference manifests itself in the behavior of the gap in the spectrum of quasiparticles in an external magnetic field h. For small fields h, a j-h phase diagram is constructed that determines the domains in which the 120 degrees and the singlet phases exist. It is established that, in the neighborhood of the second-order phase transition, the contribution, to the thermodynamic quantities, of longitudinal spin fluctuations, which are disregarded in the spin-wave description, is comparable to the contribution of transverse fluctuations. (c) 2005 Pleiades Publishing, Inc.

WOS,
Scopus,
Читать в сети ИФ
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, Krasnoyarsk, Akademgorodok, 660036, Russian Federation

Доп.точки доступа:
Bondarenko, I. N.
}
Найти похожие
10.


    Zinenko, V. I.
    Statistical mechanics of cation ordering in PbSc1/2Ta1/2O3 and PbSc1/2Nb1/2O3 solid solutions / V. I. Zinenko, S. N. Sofronova // Phys. Solid State. - 2005. - Vol. 47, Is. 12. - P. 2309-2314, DOI 10.1134/1.2142896. - Cited References: 17 . - ISSN 1063-7834
РУБ Physics, Condensed Matter
Рубрики:
PHASE-TRANSITION
   PEROVSKITE

   DISORDER

   FERROELECTRICS

   CRYSTALS

   MODEL

Аннотация: A model Hamiltonian for B cation ordering (Sc-Nb(Ta)) in PbSc1/2Nb1/2O3 and PbSc1/2Ta1/2O3 solid solutions is constructed. The parameters of the model Hamiltonian are determined from the ab initio calculation within the ionic crystal model with allowance made for the deformability and the dipole and quadrupole polarizabilities of the ions. The temperatures of the phase transition due to the ordering of the B cations are calculated by the Monte Carlo method in the mean-field and cluster approximations. The phase transition temperatures calculated by the Monte Carlo method (1920 K for PbSc1/2Ta1/2O3 and 1810 K for PbSc1/2Nb1/2O3) are consistent with the experimental data (1770 and 1450 K, respectively). The thermodynamic properties of the cation ordering are investigated using the Monte Carlo method. (c) 2005 Pleiades Publishing, Inc.

WOS,
Scopus,
Читать в сети ИФ
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, 660036, Russian Federation

Доп.точки доступа:
Sofronova, S. N.; Софронова, Светлана Николаевна; Зиненко, Виктор Иванович
}
Найти похожие
 1-10    11-20   21-28 
 

Другие библиотеки

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