拓扑半金属α2-Ti 3Al(0001)表面的电子结构理论研究  

Theoretical Investigation of the Electronic Structure of theTopological Semimetalα2-Ti 3Al(0001)Surface

作　　者：徐梦秋 杨珊珊 史倩艺 李应发[1] 廖杨芳[1] XU Mengqiu;YANG Shanshan;SHI Qianyi;LI Yingfa;LIAO Yangfang(College of Physics and Electronic Sciences,Guizhou Normal University,Guiyang 550001,China)

机构地区：[1]贵州师范大学物理与电子科学学院,贵阳550001

出　　处：《人工晶体学报》2020年第8期1562-1567,共6页Journal of Synthetic Crystals

基　　金：贵州省科学技术基金(黔科合J字[2012]2275号);贵州师范大学2019年度“大学生科研训练计划”(DK2019A015);贵州师范大学博士基金(GZNUD[2018]15号)。

摘　　要：采用基于密度泛函理论的第一性原理方法对α2-Ti 3Al(0001)表面的电子结构进行计算。结果表明:(1)α2-Ti 3Al(0001)表面的表面能为2.03 J/m 2,表面功函数为4.265 eV;(2)表面的总态密度在费米能级处达到极大值,系统呈现金属性,与块体的半金属差异明显,Ti-s、Ti-p和Al-s轨道受层数的影响较小,而Ti-d和Al-p轨道受层数的影响较大,均在费米能级处出现极大值;(3)能带结构未呈现块体的节线环,而是在费米能级附近以下的Γ点,出现一个类电子型的三带交叉点,在费米能级以上的Γ点,出现一个类空穴型的两带交叉点。The electronic structure ofα2-Ti 3Al(0001)surface was calculated by the first principle based on density functional theory.The results show that:(1)the surface energy of theα2-Ti 3Al(0001)surface is 2.03 J/m 2,and the surface work function is 4.265 eV;(2)the total density of states on the surface reaches a maximum value at the Fermi level,and the system exhibits a metallic property,which is significantly different from the semimetal of theα2-Ti 3Al bulk,Ti-s,Ti-p and Al-s orbitals are less affected by the number of layers,while Ti-d and Al-p orbitals are more affected by the number of layers,and all of them have maximum values at the Fermi level;(3)the nodal line ring is not present in the band structure of the surface,but there is a three electronlike bands crossing point atΓpoint under the Fermi level,and there is a two holelike bands crossing point atΓpoint above the Fermi level.

关 键 词：拓扑半金属 α2-Ti 3Al(0001) 电子结构 第一性原理 能带结构 态密度 

分 类 号：O485[理学—固体物理]