resumo
First principles calculations are done for a root 2 x 4 x 2 root 2 Pnma structure, which has been recently discussed in several attempts to describe experiments in complex magnetoelectric perovskites and which experimentally was shown to compete with several ferroelectric phases. This makes these materials extremely attracting as switchers, starters, field-stimulated capacitors, high-voltage converters, transmitters, etc. The relative energies of the root 2 x 4 x 2 root 2 Pnma structure have been calculated from first principles and analyzed as a function of pressure in BiFeO3. The stability of two polymorphs of the root 2 x 4 x 2 root 2 Pnma structure has been studied for solid solution BiFe1/2Sc1/2O3. The main distortions and relative energies of these two polymorphs in BiFe1/2Sc1/2O3, in terms of Pm (3) over barm parent symmetry, have been calculated from first principles as well.
palavras-chave
PHASE-TRANSITIONS; HIGH-PRESSURE; PEROVSKITE
categoria
Physics
autores
Prosandeev, SA; Khalyavin, DD; Raevski, IP; Salak, AN; Olekhnovich, NM; Pushkarev, AV; Radyush, YV
nossos autores
Andrei Salak
Investigador Principalagradecimentos
This work was partially supported by the Russian Foundation for Basic Research (Projects No. 12-08-00887_a, No. 14-02-90024 Bel_a, and No. 14-02-90438 Ucr_a), Ministry of education of Russian Federation (research project 2132, task No. 2014/174) and by the Belarus Republican Foundation for Basic Research (Project No. T14R-019). S. P. appreciates discussions with Laurent Bellaiche and acknowledges ONR Grants No. N00014-11-1-0384 and No. N00014-12-1-1034.