氧离子导体β-La_2Mo_2O_9结构性质的第一性原理研究  

Research on crystal structure of β-La2Mo_2O_9 using first-principle theory

作　　者：侯春菊[1] 张旭[2] 董太源[1] 孔详山[3] 

机构地区：[1]江西理工大学理学院,赣州341000 [2]江西理工大学材料与化工程学院,赣州341000 [3]中国科学院固体物理研究所,合肥230031

出　　处：《四川大学学报（自然科学版）》2010年第1期102-108,共7页Journal of Sichuan University(Natural Science Edition)

基　　金：国家自然科学基金(10674135)

摘　　要：采用第一性原理方法研究了β-La_2Mo_2O_9结构性质.研究发现结构中Mo和周围的O形成MoO_4或MoO_5两种形式的多面体,La则形成LaO_8和LaO_7多面体.O(1)、O(2)、O(3)三种氧位置的占有率分别为100%、91.7%和25 /%,与实验相符.对Mo—O(1)键长分析表明,在MoO_4和MoO_5两种多面体中Mo-O(1)键长劈裂成两种键长形式.所有结构组态可通过P2_13空间群的相应操作而互相转换,显示结构具有P2_13空间群的对称性.模拟结果可能是β-La_2Mo_2O_9结构在空间的局域或者本征极小结构.The structure ot β-La2Mo2O9 was stufllea oy using two methods based on first-principles theory. Each Mo cation is surrounded by four or five O-ions, forming MoO4 tetrahedra or MoO5 hexahedra, La has LaO8 and LaO7 polyhedra. It is found that the occupancies of three crystallographic distinct O sites O（1）, 0（2） and 0（3） are 100%, 91.7% and 25%, respectively, consistent with experiments. The analysis of Mo--O（1） bond length demonstrates the split of O（1） sites into two groups. All configurations are related to each other by one of the structure observed experimentally may inherent structures. symmetry operations of P213 space group, suggesting that interpreted as a time and spatial average of these local or

关 键 词：氧离子导体 β-La2Mo2O9 第一性原理 氧空位 

分 类 号：O469[理学—凝聚态物理]