Труды сотрудников института физики

/ V. S. Zhandun, N. G. Zamkova, V. I. Zinenko // J. Exp. Theor. Phys. - 2008. - Vol. 106, Is. 6. - P. 1109-1117, DOI 10.1134/S1063776108060101. - Cited References: 29 . - ISSN 1063-7761РУБ Physics, Multidisciplinary

Аннотация: The lattice vibration spectra, rf permittivity, and dynamic Born charges of disordered PbB(1/2)'B(1/2)'' O(3) (B' = Ga, In, Lu; B '' = Nb, Ta) solid solutions are calculated in terms of the generalized Gordon-Kim model. All the compounds are found to have soft modes related to the center (Gamma(15)) and boundary point R (R(15)) of the Brillouin zone; the frequencies of these modes are close. The ferroelectric phase transition temperatures and the spontaneous polarization in the ferroelectric phase are calculated for the solid solutions using a model Hamiltonian in the local mode approximation and the Monte Carlo method. These temperatures for the tantalum compounds are found to be higher than for the niobium compounds, and temperature t(s) increases with the atomic number of ion B'. A model where the antiferroelectric state is related to the condensation of modes Gamma(15) and R(15) is proposed. It is found that, for all compounds except for PbSc(1/2)Nb(1/2)O(3) and PbSc(1/2)Ta(1/2)O(3), the ferroelectric phase, which is only related to the condensation of mode R(15), and the antiferroelectric phase have similar energies. In PbIn(1/2)Ta(1/2)O(3), the antiferroelectric phase turns out to be energetically favorable.

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Держатели документа:
[Zhandun, V. S.
Zamkova, N. G.
Zinenko, V. I.] Russian Acad Sci, LV Kirensky Phys Inst, 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:
Zamkova, N. G.; Замкова, Наталья Геннадьевна; Zinenko, V. I.; Зиненко, Виктор Иванович; Жандун, Вячеслав Сергеевич

/ E. G. Maksimov, V. I. Zinenko, N. G. Zamkova // Phys. Usp. - 2004. - Vol. 47, Is. 11. - P. 1075-1099, DOI 10.1070/PU2004v047n11ABEH001796. - Cited References: 90 . - ISSN 1063-7869РУБ Physics, Multidisciplinary

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.

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Scopus

Держатели документа:
Russian Acad Sci, PN Lebedev Phys Inst, Moscow 119991, Russia
Russian Acad Sci, LV Kirensky Phys Inst, Siberian Div, Krasnoyarsk 660036, Russia
ИФ СО РАН
P N Lebedev Physics Institute, Russian Academy of Sciences, Leninskii prosp. 53, 119991 Moscow, Russian Federation
L V Kirenskii Inst. of Phys., Siberian Division, Russian Academy of Sciences, Akademgorodok, 660036 Krasnoyarsk, Russian Federation

Доп.точки доступа:
Zinenko, V. I.; Зиненко, Виктор Иванович; Zamkova, N. G.; Замкова, Наталья Геннадьевна