Ag/SnO2复合材料界面结合稳定性的第一性原理研究  

First-principles Study on Interface Bonding Stability of Ag/SnO Composites

作　　者：刘周 王景芹[1,2] 朱艳彩[1,2] 陈令 于双淼 Liu Zhou;Wang Jingqin;Zhu Yancai;Chen ling;Yu Shuangmiao(State Key Laboratory of Reliability and Intelligence of Electrical Equipment,Hebei University of Technology,Tianjin 300130,China;Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province,Hebei University of Technology,Tianjin 300130,China)

机构地区：[1]河北工业大学省部共建电工装备可靠性与智能化国家重点实验室,天津300130 [2]河北工业大学河北省电磁场与电器可靠性重点实验室,天津300130

出　　处：《稀有金属》2020年第7期729-734,共6页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51777057)资助。

摘　　要：AgSnO2作为替代AgCdO的理想材料受到越来越多的重视,但是目前对该材料的理论研究仅仅停留在对增强相SnO2的掺杂改性上,而对于AgSnO2界面结合情况的研究非常少。采用基于密度泛函理论的第一性原理法,使用CASTEP软件计算SnO2和Ag的代表性低指数面的表面能,选取表面能较低的自由表面建立三组稳定的界面模型,分别对各个界面模型的结合能、态密度、Mulliken布居进行计算分析,预测最稳定的结合界面。结果表明:Ag(111)面和SnO2(110)面的表面能最低;由Ag(111)面和SnO2(100)两个自由表面所构建的界面模型的结合能的绝对值最大,并且Ag(111)/SnO2(100)的O的态密度高于其他两组界面,电子浓度最大,在-3 eV附近Ag-4d轨道与O-2p轨道同时存在尖峰,产生的杂化作用较强,提高了电子跃迁率,降低了两个自由表面的排斥作用,稳定性最好;Ag(111)/SnO2(110)界面模型的结合能居中,并且在-5 eV附近,Sn-5p轨道的尖峰位置与Ag-4d轨道的尖峰位置相近,重叠部分面积大,杂化作用强,形成的Ag-Sn键共价性强,但由于没有形成Ag-O键因此其稳定性居中;Ag(111)/SnO2(101)界面模型的稳定性最弱,Ag-O键和Ag-Sn键的形成对界面的稳定结合起到重要作用。As an ideal material to replace AgCdO,AgSnO2 received more and more attention.However,the theoretical research on this material only stayed on the doping modification of the reinforcing phase SnO2,there was very little research on the interface bonding of AgSnO2.This paper adopted the first-principles method based on density functional theory and selected free surfaces with a low surface energy to create three stable interface models by using CASTEP software to calculate the surface energy of the representative low index surface of SnO2 and Ag.By calculating and analyzing the cohesive energy,density of states,and Mulliken populations of each interface model,the most stable interface could be predicted.The results showed that the surface energy of Ag(111)and SnO2(110)was the lowest.The interface model constructed by Ag(111)and SnO2(100)had the largest absolute value of cohesive energy,moreover,the density of O of Ag(111)/SnO2(100)was higher than that of the other two groups,and the electron concentration was the largest,there were spikes in the Ag-4 d orbital and O-2p orbital near-3 eV,which produced a strong hybridization effect,improved the electron transition rate,reduced the repulsion of the two free surfaces,therefore,the stability of Ag(111)/SnO2(100)was the best.The interface bonding energy of Ag(111)/SnO2(110)was centered,and in the vicinity of-5 eV,the peak position of the Sn-5p orbital was closer to the peak position of the Ag-4 d orbital,the overlap area was large,the hybridization effect was strong,the formed Ag-Sn bond was highly covalent,but no Ag-O bond was formed so its stability was centered;The stability of the Ag(111)/SnO2(101)interface model was the weakest,and the formation of Ag-O bond and Ag-Sn bond played an important role in maintaining the stability of the interface.

关 键 词：Ag/SnO2复合材料 第一性原理 界面结合 稳定性 

分 类 号：TM501[电气工程—电器]