RS、ZB、CsCl结构的XC(X=Mg、Ca、Sr、Ba)第一性原理计算  

First-principles calculation of XC(X=Mg,Ca,Sr,Ba)under the structure of RS,ZB and CsCl

作　　者：封文江[1] 谢金峰 高雅 徐乾浩 刘岩 赵雪桐 FENG Wenjiang;XIE Jinfeng;GAO Ya;XU Qianhao;LIU Yan;ZHAO Xuetong(College of Physical Science and Technology, Shenyang Normal University, Shenyang 110034, China)

机构地区：[1]沈阳师范大学物理科学与技术学院,沈阳110034

出　　处：《沈阳师范大学学报（自然科学版）》2021年第2期132-136,共5页Journal of Shenyang Normal University:Natural Science Edition

基　　金：国家自然科学基金资助项目(11674233);辽宁省“百千万人才工程”资助项目;辽宁省科技厅自然科学基金资助项目(2019-ZD-0484)。

摘　　要：XC是ⅡA族元素(碱土金属)与C原子形成的化合物,此类化合物是本身不含有过渡金属元素、不含磁性原子却能产生铁磁性的化合物,因此引起了人们的广泛关注。为探究XC化合物材料的性能,预测其用途,采用基于密度泛函理论的第一性原理对XC进行模拟计算。使用Materials Studio 6.0对XC化合物进行建模优化,确定XC在rocksalt(RS)、zinc-blende(ZB)、CsCl结构时自旋都向上,且当MgC、CaC、SrC、BaC处于RS结构时的磁性主要来源于C原子的能级劈裂。计算获得平衡态的晶格常数分别为4.665、5.284、5.668、6.000,并基于此计算材料的磁学性质与力学性质。研究发现,MgC材料的能带结构和态密度具有金属性特征,CaC材料的能带结构和态密度具有近半金属的特征,而SrC、BaC材料具有半金属性的特征。通过对XC化合物的力学性能计算,发现CaC与BaC是2种具有良好的延展性的材料。XC are compounds ofⅡA group element(alkaline earth metal)and C atoms.This kind of compounds does not have transition metal elements,an excluding magnetic atoms but having ferromagnetic compounds,and therefore has attracted widespread attention.In order to explore the properties of XC compound materials and predict its use,in this paper we adopt the first-principles of density functional theory to simulate XC.Materials Studio6.0 is used to model and optimize XC compounds.It is found that the spin of XC in rocksalt(RS),zinc-blende(Zb)and CsCl structures are all upward,and the magnetic properties of MgC,CaC,SrC and BaC in RS structures mainly came from the energy level splitting of C atoms.The lattice constants of the equilibrium state are 4.665,5.284,5.668 and 6.000respectively,and the magnetic and mechanical properties of the material are calculated based on this.It is found that the energy band structure and state density of MgC materials have the characteristics of metal,the energy band structure and state density of CaC materials have the characteristics of semi-metal,and SrC and BaC materials have the characteristics of semi-metal.By calculating the mechanical properties of XC compound,it is found that CaC and BaC are two kinds of materials with good ductility.

关 键 词：密度泛函理论 半金属性 磁学性质 碱土金属 XC 

分 类 号：O469[理学—凝聚态物理]