基于第一性原理的钙钛矿BaFe0.5Nb0.5O3B位的有序结构  

First principle study of the B-site ordered structure perovskite BaFe_(0.5)Nb_(0.5)O_3

作　　者：纪登辉 张娅 王淑玲 李秀玲[3] 张聪敏 曾志伟 

机构地区：[1]六盘水师范学院电气工程学院,六盘水市光电信息技术重点实验室,贵州六盘水553004 [2]河北工程大学数理科学与工程学院,河北邯郸056038 [3]河北师范大学物理科学与信息工程学院,河北省新型薄膜材料实验室,河北石家庄050024

出　　处：《河北大学学报（自然科学版）》2017年第6期595-604,共10页Journal of Hebei University(Natural Science Edition)

基　　金：国家自然科学基金资助项目(11504078);六盘水师范学院高层次人才科研启动基金(LPSSYKYJJ201404);六盘水师范学院MIT创新团队项目(LPSSYKJTD201402);六盘水师范学院物理电子学院级重点学科(LPSSYZDXK201502);贵州省教育厅自然科学重点研究项目(KY2015379);贵州省科技厅联合基金(LH[2014]7449,LH[2014]7456)

摘　　要：基于第一性原理,利用Materials Studio计算软件中CASTEP软件包构建出双钙钛矿材料BaFe_(0.5)Nb_(0.5)O_3的4种位形,研究B位有序无序对其结构和物理性能的影响.通过GGA+PBE关联函数对4种位形结构分别进行几何优化和能量优化,根据能量最低原理,获得最终优化后的几何结构与各项物理性能.计算结果表明:反铁磁的能量最低且为半导体,为最优的几何结构,并且通过紫外可见吸收实验证明了带隙的存在;铁磁结构与反铁磁结构自旋存在夹角,属于半金属;在费米能级附近,d电子与p电子的相互作用明显,对态密度的贡献最大;在低频率范围内,反铁磁结构Ba-AFM出现吸收峰最早,但吸收峰强度最低.Based on the first principle calculations,the four kinds of B-site order or disorder BaFe_(0.5)Nb_(0.5)O_3 were constructed using the CASTEP software package,the impacts of the order and disorder at B sites on the structure and physical properties of the BaFe_(0.5)Nb_(0.5)O_3 perovskite were investigated.The exchange-correlation potential with Perdew-Burke-Ernzerhof(PBE)gradient corrected functional is adopted.Calculated results show that the antiferromagnetic configuration exhibits the direct band with a minimumenergy,which is consistent with the Uv-vis absorption experiment result.Near the Fermi level,the interaction between d and p electron contributes the most to the density of states.At the low frequency range,antiferromagnetic configuration possesses the lowest absorption peak location,and the weakest intensity.

关 键 词：双钙钛矿 第一性原理 带隙 能量最低原理 态密度 

分 类 号：O469[理学—凝聚态物理]