First-principles calculation of influences of La-doping on electronic structures of KNN lead-free ceramics

作     者：Ting Wang Yan-Chen Fan Jie Xing Ze Xu Geng Li Ke Wang Jia-Gang Wu Jian-Guo Zhu 王挺;樊晏辰;邢洁;徐泽;李庚;王轲;吴家刚;朱建国

作者机构：College of Materials Science and EngineeringSichuan UniversityChengdu 610064China School of Materials Science and EngineeringBeihang UniversityBeijing 100191China State Key Laboratory of New Ceramics and Fine ProcessingSchool of Materials Science and EngineeringTsinghua UniversityBeijing 100084China 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2020年第29卷第6期

页      面：512-516页

核心收录：

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：National Natural Science Foundation of China(Grant Nos.51572143 51822206 and 51932010) 

主　　题：(K0.5Na0.5)NbO3(KNN) piezoelectricity first-principles calculation electronic structure 

摘      要：The electronic structures of lead-free piezoceramic(K0.5Na0.5)NbO3(KNN)and La-doped KNN((K0.5Na0.5)0.994La0.006NbO3)are studied by using first principles calculation on the basis of density functional theory(DFT).The results reveale that the piezoelectricity stems from strong hybridization between the Nb atom and the O *** the same time,the K or Na atoms are replaced by the La doping atoms,which brings about the anisotropic *** La doping reduces the forbidden band,at the same time it makes Fermi surfaces shift toward the energetic conduction band(CB)of *** the increase of La-doping intent,the phase structure of KNN extends from O-phase to T-phase and improves the piezoelectric properties of KNN.