【作者】 胡萌； 李春梅； 惠梁梁； 谢中静； 陈宽宽； 陈志谦；

【Author】 HU Meng;LI ChunMei;Liangliang Hui;Zhongjing Xie;Kuankuan Chen;CHEN ZhiQian;Faculty of Materials and Energy,Southwest University;

【机构】 西南大学材料与能源学部；

【摘要】 基于第一性原理密度泛函理论,本文分析了Co₂MnX（X=Al,Si,Sb）三种Heusler合金的结构和电子性质,以及热学性质中的最小热导率。将优化后的晶格参数以及总磁矩和现有的实验数据相比,结果误差较小。计算后的弹性常数满足稳定性判据,形成焓、结合能的计算结果都为负数,且Co₂MnSi最为稳定并最易于合成。能带结构的分析表明Co₂MnSi和Co₂MnSb自旋向下的能带结构出现明显的带隙,是典型的半金属铁磁体,但Co₂MnAl的能带结构却不能显示真实的半金属性。而态密度主要是Co原子和Mn原子的3d轨道贡献。另外Co₂MnX（X=Al,Si,Sb）的热导率分析显示出Co₂MnSb的热导率最小。更多还原

【Abstract】 Based on the first-principles density functional theory,the structures,electronic properties,and thermal conductivities of Co₂MnX（X=A1,Si,Sb） are studied.Compared with the existing experimental data,the errors of the optimized lattice parameters and total magnetic moments are negligibly small.The calculated elastic constants agree well with stability criteria.And the results of formation enthalpy and cohesive energy of Co₂MnX（X=A1,Si,Sb） are negative.Co₂MnSi is the most stable and easiest to synthesis one.It is found that the minority spin states band structure of Co₂MnSi and Co₂MnSb display significant band gaps.This reslut shows Co₂MnSi and Co₂MnSb are typical half-metallic ferromagnets.However,Co₂MnAl is unable to show a real half-metal property.The densities of states are mainly related to 3d orbital of Co and Mn atoms.In addition,the thermal conductivity of Co₂MnSb is minimum.更多还原