(1. 江苏理工学院 江苏省先进材料设计与增材制造重点实验室，常州 213001；
2. 中南大学 材料科学与工程学院，长沙 410083)
摘 要: 运用第一性原理平面波赝势方法计算了Mo(111)/MoSi2(110)的界面结构，并通过元素界面偏析能的计算确定了Al、Cr和Nb在Mo(111)/MoSi2(110)的偏析位置，结合脱粘功和差分电荷密度揭示了Al、Cr和Nb对Mo/MoSi2界面结合强度的影响。结果表明：Si顶位型配位方式的界面能最小，最为稳定，在Mo(111)/MoSi2(110)界面结构中倾向于以Si顶位型配位方式结合，其界面分离面在近界面MoSi2(110)一侧的亚界面层。Nb对界面结合不利，Cr可适当提高界面结合强度，而Al对界面强度的影响取决于其界面覆盖度。究其原因是由于Nb在界面偏析形成的Nb—Si键相比于Mo—Si键有明显减弱，Cr形成的Cr—Si键略有增强，而Al的界面覆盖度对形成的Mo—Al键强弱影响较大。
关键字: Mo/MoSi2；界面能；脱粘功；第一性原理
（1. Jiangsu Key Laboratory of Advanced Materials Design and Additive Manufacturing, Jiangsu University of Technology, Changzhou, 213001;
2. School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The interface structures of Mo(111)/MoSi2(110) were calculated by the first-principle plane wave pseudopotential method. The segregation positions of Al, Cr and Nb at Mo(111)/MoSi2(110) were determined by the segregation energies, and their effects on the interface strength were revealed by the works of separation and deformation charge density. The results show that the interface energy of the Si-top coordination is the smallest. The Mo(111)/MoSi2(110) structure prefers to Si Top coordination, and its separation surface is the sub-interface on the MoSi2 side. Nb is unfavorable to interface strength, Cr can improve interface strength, and the influence of Al on interface strength depends on its interface coverage. The reason is that Nb—Si bond induced by Nb is significantly weaker than Mo—Si bond, while Cr—Si bond induced by Cr are slightly stronger than Mo—Si bond. And the interface coverage of Al has a great influence on the strength of Mo—Al bonds.
Key words: Mo/MoSi2; interface energy; works of separation; first-principle calculation
