First-principles investigation of vacancies in LiTaO3

作者：He, Wenhao; Gao, Xing^*; Pang, Lilong; Wang, Dong; Gao, Ning; Wang, Zhiguang

来源：Journal of Physics: Condensed Matter , 2016, 28(31): 315501.

DOI：10.1088/0953-8984/28/31/315501

• lithium tantalate
• formation energy
• vacancy
• light absorption

Formation energies of neutral and charged vacancies in lithium tantalate, as well as their electronic states have been investigated through first-principles calculations. It is found out that V-O(2+), V-Li(1-) and V-Ta(5-) 5 are the most energy favorable vacancies on O, Li and Ta sites respectively. The formation energy of vacancy on the O site is lower in oxygen poor environments than that in oxygen rich environments, and the formation energy of vacancy on the cation site is lower in oxygen rich environments than that in oxygen poor environments. Among all types of neutral vacancies considered in this study, the energy of Li partial Schottky reaction, 2V(Li)(1-) + V-O(2+), is the lowest at almost all considered chemical environments. Taking into account the distribution of vacancy induced energy levels, we suggest that either V-O(0) or V-O(1+) is responsible for the light absorption band around 460 nm observed in annealed LiTaO3 crystal.

• 出版日期2016-8-10
• 单位中国科学院近代物理研究所; 中国科学院大学