Quantum-chemical modeling of squaric acid ferroelectric behavior

The properties of layered 2d-ferroelectric and at the same time 3d-antiferroelectric materials H2C4O4/D 2C4O4 are studied by quantum-chemical approach using pseudospin formalism in frames of Ising-type model Hamiltonian with tunneling terms. This Hamiltonian parameters (that are Ω - tunneling integral and Jij- Ising parameters) for both materials were obtained by means of RHF, MP2-MP4 and DFT/B3LYP calculations for different clusters which simulate characteristic fragments of materials crystalline structure. Resulting Ω and Jij values for crystals at hand were used in the limits of two mean field approximations that allow explaining main peculiarities of the observed order-disorder phase transition. The nature is discussed of the Bethe cluster lowest energy level splitting that has been introduced for correct description of this transition. Copyright © 2010 Wiley Periodicals, Inc.

Авторы
Dolin S.P.1 , Levin A.A.1 , Mikhailova T.Yu.1 , Solin M.V.2 , Zinova N.V. 3
Издательство
John Wiley and Sons Inc.
Номер выпуска
11
Язык
Английский
Страницы
2671-2676
Статус
Опубликовано
Том
111
Год
2011
Организации
  • 1 N.S. Kurnakov Institute of General and Inorganic Chemistry RAS, 119991 Moscow, Russian Federation
  • 2 Russian State Social University, 129256 Moscow, Russian Federation
  • 3 People's Friendship University of Russia, 117198 Moscow, Russian Federation
Ключевые слова
ferroelectric materials; quantum-chemical modeling; squaric acid; structural phase transition
Дата создания
19.10.2018
Дата изменения
19.10.2018
Постоянная ссылка
https://repository.rudn.ru/ru/records/article/record/2506/