Analysis of soft optical modes in hexagonal BaTiO3: transference of perovskite local distortions

Дата и время публикации : 2000-02-11T10:11:45Z

Авторы публикации и институты :
Jorge Iniguez (Universidad del Pais Vasco)
Alberto Garcia (Universidad del Pais Vasco)
J. M. Perez-Mato (Universidad del Pais Vasco)

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 4 pages, 3 eps figures
Первичная категория: cond-mat.mtrl-sci

Все категории : cond-mat.mtrl-sci

Краткий обзор статьи: We have performed detailed first-principles calculations to determine the eigenvectors of the zone-center modes of hexagonal BaTiO3 and shown that the experimentally relevant low-energy modes (including the non-polar instability) can be represented as suitable combinations of basic local polar distortions associated with the instability of the cubic perovskite phase. The hexagonal structure provides a testing ground for the analysis of the influence of the stacking of TiO6 octahedra: the occurrence of relatively high-energy chains of dipoles highlights the importance of local effects related to the coherent hybridization enhancement between Ti and O ions. Our results provide simple heuristic rules that could be useful for the analysis of related compounds.

Category: Physics