(1. 江蘇理工學(xué)院 江蘇省先進材料設(shè)計與增材制造重點實驗室，常州 213001；
2. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 運用第一性原理平面波贗勢方法計算了Mo(111)/MoSi2(110)的界面結(jié)構(gòu)，并通過元素界面偏析能的計算確定了Al、Cr和Nb在Mo(111)/MoSi2(110)的偏析位置，結(jié)合脫粘功和差分電荷密度揭示了Al、Cr和Nb對Mo/MoSi2界面結(jié)合強度的影響。結(jié)果表明：Si頂位型配位方式的界面能最小，最為穩(wěn)定，在Mo(111)/MoSi2(110)界面結(jié)構(gòu)中傾向于以Si頂位型配位方式結(jié)合，其界面分離面在近界面MoSi2(110)一側(cè)的亞界面層。Nb對界面結(jié)合不利，Cr可適當提高界面結(jié)合強度，而Al對界面強度的影響取決于其界面覆蓋度。究其原因是由于Nb在界面偏析形成的Nb—Si鍵相比于Mo—Si鍵有明顯減弱，Cr形成的Cr—Si鍵略有增強，而Al的界面覆蓋度對形成的Mo—Al鍵強弱影響較大。
關(guān)鍵字: Mo/MoSi2；界面能；脫粘功；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
