YFe_2B_2电子结构的第一性原理计算  

Electronic structure of YFe_2B_2 by first-principles calculation

作　　者：谭兴毅[1] 金克新[1] 陈长乐[1] 周超超[1] 

机构地区：[1]西北工业大学凝聚态结构与性质陕西省重点实验室,西安710072

出　　处：《物理学报》2010年第5期3414-3417,共4页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:50331040和50702046);西北工业大学基础研究基金(批准号:NPU-FFR-JC200821);西北工业大学"翱翔之星"项目资助的课题~~

摘　　要：基于密度泛函理论,从头计算了具有ThCr2Si2型四方晶系的稀土金属化合物YFe2B2体相的物理特性.能量计算结果表明YFe2B2体相处于顺磁金属态;而能带结构、态密度、布居数以及差分电荷分布的计算结果表明Y原子的5s,5p电子具有很强的局域性;Fe原子的3d电子和B的1s,2s和2p电子强烈耦合,使得最近邻Fe原子与B原子形成了Fe—B共价键;最近邻的两个Fe原子之间由于其3d电子相互作用形成金属键,Fe原子与Y原子的键合方式为反键态;说明YFe2B2的基态为顺磁三元合金.By means of first-principles calculations,we have investigated the band structrue,density of states （ DOS） and electron density difference of the compound YFe2B2. For the exchange correction energy,we employ GGA in the form of PBE. The interactions between valence electrons and ionic core are represented by the ultrasoft pseudo potential. The results show that the compound YFe2B2 is paramagnetic. The 5s and 5p states of Y atoms are in a strong local state. The Fe and B atoms form nearest-neighbor bonds associated with Fe—B bonding. The Fe 3d-like bands with low E （ k） dispersion participate in metallic-like Fe-Fe bonds. The Fe 3d states have an admixture of anti-bonding Y 4d states. In a word,YFe2B2 in the ground state is a paramagnetic ternary alloy.

关 键 词：稀土金属化合物 第一性原理计算 能带结构 态密度 

分 类 号：O614.322[理学—无机化学]