Sr_3AlO_4F晶体中掺杂Ba^(2+),Ca^(2+)离子占据不同Sr^(2+)格位倾向性的第一性原理研究  

Site Preferences of Ba^(2+) and Ca^(2+) Dopants on Different Sr^(2+) Sites in the Sr_3AlO_4F Crystal: a First-Principles Study

作　　者：杨帆[1] 张玲玉[1] 宁利新[1] 

机构地区：[1]安徽师范大学物理与电子信息学院,安徽芜湖241000

出　　处：《安徽师范大学学报（自然科学版）》2012年第2期130-135,共6页Journal of Anhui Normal University(Natural Science)

基　　金：国家自然科学基金(10804001)

摘　　要：通过比较第一性原理计算总能量得出碱金属离子Ba2+和Ca2+取代占据氟氧化物晶体Sr3AlO4F中两种不同Sr格位时,Ba2+倾向占据10配位的Sr(1)位,而Ca2+倾向占据8配位的Sr(2)位,与实验分析结果一致.基于上述优化结构,通过键价求和计算和畸变指数分析,得出Sr3AlO4F中Sr(1)格位离子严重未饱和成键,倾向于被较大Ba2+离子取代占据;而Sr(2)格位离子略微过饱和成键,倾向于被较小Ca2+离子取代占据.The site preferences of the dopant Ba2＋ and Ca2＋ ions on the two different Sr2＋ sites in the Sr3AlO4F crystal have been investigated from first-principles.It is found that Ba2＋ and Ca2＋ prefer to reside on the 10-coordinated Sr（1） and 8-coordinated Sr（2） sites,respectively,in agreement with experimental analyses.These site preferences are then explained based on calculations of the bond-valence-sum and analyses of distortion indices for the optimized geometries.The results indicate that the Sr2＋ ions at the Sr（1） site are seriously over-bonded,while at the Sr（2） site the bond is slightly unsaturated.

关 键 词：Sr3AlO4F 格位占据倾向性 第一性原理计算 键价求和计算 

分 类 号：O77[理学—晶体学]