Open AccessFIRST-PRINCIPLES STUDY OF TETRAGONAL FERROELECTRIC STRUCTUER OF K(Ta0.56Nb0.44)O3
Author(s) -
PENG YI-PING,
Yuanxu Wang,
Lei Zhang,
Peilin Zhang,
W. L. Zhong
Publication year - 2000
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.49.1140
Subject(s) - tetragonal crystal system , ferroelectricity , octahedron , materials science , condensed matter physics , displacement (psychology) , center (category theory) , phase (matter) , physics , crystallography , crystal structure , chemistry , dielectric , optoelectronics , quantum mechanics , psychology , psychotherapist
Based on the results of total-energy calculations using full-potential linearized augmented plane wave method within the generalized gradient approximation (GGA),we determined the tetragonal fine structure of K(Ta0.56Nb0.44)O3i.e.,the equilibrium configuration of B-site cations (Ta and Nb)in the ferroelectric phase. Ta is found to have an off-center displacement,relative to the oxygen octahedron,of about 0.005nm along [001]. The off-center displacement of Nb is as large as 0.016nm,thus makes a major contribution to the occurrence of the ferroelectric instability.