Theoretical investigation on BaTiO3 with periodic density functional theory BLYP method

Citation
Zx. Chen et al., Theoretical investigation on BaTiO3 with periodic density functional theory BLYP method, CHEM PHYS, 270(2), 2001, pp. 253-261
Citations number
47
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
CHEMICAL PHYSICS
ISSN journal
0301-0104 → ACNP
Volume
270
Issue
2
Year of publication
2001
Pages
253 - 261
Database
ISI
SICI code
0301-0104(20010801)270:2<253:TIOBWP>2.0.ZU;2-#
Abstract
The electronic structures and bonding modes of BaTiO3 in the cubic and the distorted tetragonal structures have been investigated with periodic DFT-BL YP method. The results show that Ti displacement makes the charge transfer from O atoms to Ba and Ti atoms. Ba atoms might play a more important role in distributing the transferred charges than one has imagined. Our results also indicate that Ti displacement enhances the Ti-O and Ba-O(2) bonds. Onl y Ba-O(1) is slightly weakened. The pi bonding interaction of 3d(xz)(Ti)-2p (x)[O(1)] and 3d(yz)(Ti)-2p(y)[O(1)] favors the tetragonal phase whereas th e a bond 4p(z)(Ti)-2p(z)[O(1)] favors the paraelectric cubic phase. Our res ults are consistent with the vibronic theory that the ferroelectric instabi lity of BaTiO3 is due to the formation of new covalency by distortion. (C) 2001 Elsevier Science B.V. All rights reserved.