Electronic Structure and Ferroelectric Behavior of Lanthanum Substituted Bismuth Titanate

作者：R. Machado, M. G. Stachiotti · 发表于：Ferroelectrics · 年份：2006 · DOI：10.1080/00150190600678608 · 被引用次数：9 · 研究领域：Ferroelectric and Piezoelectric Materials、Multiferroics and related materials、Microwave Dielectric Ceramics Synthesis

The effect of substituting La for Bi atoms in Bi 4 Ti 3 O 12 is investigated from first-principles calculations using the full-potential linearized augmented plane wave (LAPW) method. A comparative study of the electronic structure and lattice-dynamics properties of Bi 4 Ti 3 O 12 and La 2 Bi 2 Ti 3 O 12 shows the role of covalent bonding in the ferroelectric instabilities. The displacement patterns displayed by unstable zone-center phonon modes and a detailed analysis of the orbital contribution to the valence band illustrate the importance of Bi (La)-O interactions for the ferroelectric behavior of the doped material.