First-principles study of electronic properties and stability of Nb_5SiB_2(001) surface

作     者：许昱江子 尚家香 王福合 

作者机构：Key Laboratory of Aerospace Materials and Performance(Ministry of Education)School of Materials Science and EngineeringBeihang University Department of PhysicsCapital Normal University 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2011年第20卷第3期

页      面：366-372页

核心收录：

学科分类：0809[工学-电子科学与技术（可授工学、理学学位）] 07[理学] 070205[理学-凝聚态物理] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0702[理学-物理学] 

基　　金：supported by the National Natural Science Foundation of China (Grant No. 50771004) 

主　　题：first principles NbsSiB2 surface electronic properties surface stability 

摘      要：The density functional calculations are performed to study the electronic structure and stability of Nb5SiB2 （001） surface with different terminations. The calculated cleavage energies along the （001） planes in Nb5SiB2 are 5.015 J · m-2 and 6.593 J· m-2 with the break of Nb=Si and Nb-NbB bonds, respectively. There exists a close correlation between the surface relaxation including surface ripple and the cleavage energy： the larger the cleavage energy, the larger the surface relaxation. Moreover, the surface stability of the NbsSiB2 （001） with different terminations has been investigated by the chemical potential phase diagram. From a thermodynamics point of view, the four terminations can be stabilized under different conditions. In chemical potential space, NbB （Nb） and Nb （Si） terminations are just stable in a small area, whereas Si （Nb） and Nb （NbB） terminations are stable in a large area （the letters in brackets represent the subsurface atoms）.