摘要
采用基于密度泛函理论的第一性原理计算,研究了Nb_(2)Al(100)表面不同终止端的电子结构、表面能和热力学性质。计算结果表明,由于表面弛豫和表面态的形成,所有终止端表面的电子结构均表现出增强的金属性质和减弱的共价性质。根据不同终止端表面的表面能计算,分析了非化学计量比表面的稳定性。在富含Nb和Al的条件下,C终止端表面(Nb_(22)Al_(12))是热力学最稳定的表面。此外,计算了Nb_(2)Al(100)表面的功函数,表明该表面获得和失去电子的能力与形成前的纯元素表面相似。
The electronic structures,surface energies and thermodynamic properties of different terminated Nb_(2)Al(100)surfaces were studied using first-principle calculations based on density functional theory.Results show that the calculated electronic structures present the enhanced metallic character and decrease covalent character for all terminated surfaces,which are attributed to the surface relaxations and the formation of surface states.According the calculated surface energies of different terminations,the surface stabilities of non-stoichiometric surfaces were analyzed.The C terminated surface(Nb_(22)Al_(12))is the most thermodynamically stable surface under both Nb-rich and Al-rich conditions.Moreover,the work function of Nb_(2)Al(100)surface was calculated,indicating that its ability to gain and lose electrons on the surface is similar to that of pure elemental surface before formation.
作者
洪丹
焦振
曾薇
刘福生
唐斌
刘其军
Hong Dan;Jiao Zhen;Zeng Wei;Liu Fusheng;Tang Bin;Liu Qijun(Key Laboratory of Advanced Technologies of Materials,Ministry of Education,School of Physical Science and Technology,Southwest Jiao-tong University,Chengdu 610031,China;College of Medical Technology,Chengdu University of TCM,Chengdu 610075,China;Sichuan Provincial Key Laboratory(for Universities)of High Pressure Science and Technology,Southwest Jiaotong University,Chengdu 610031,China;State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi’an 710072,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2021年第5期1596-1601,共6页
Rare Metal Materials and Engineering
基金
Sichuan Science and Technology Program(2018JY0161)
Fundamental Research Funds for the Central Universities(2682019LK07)
State Key Laboratory of Solidification Processing in NWPU(SKLSP201843)。
关键词
金属间化合物
密度泛函理论
电子结构
表面性质
intennetallic
density functional theory
electronic structure
surface properties