镧铱硅电子结构与成键机理的第一性原理研究  

Electronic structure and bonding mechanism of La-Ir-Si:A first-principles study

作　　者：刘君民[1,2] 孙立忠[1,2] 陈元平[1,2] 张凯旺[1,2] 袁辉球[3] 钟建新[1,2] 

机构地区：[1]湘潭大学量子工程与微纳能源技术湖南省高校重点实验室,湘潭411105 [2]湘潭大学材料与光电物理学院,湘潭411105 [3]浙江大学物理系,杭州310027

出　　处：《物理学报》2009年第11期7826-7832,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10874143;10774127);教育部博士点新教师基金(批准号:20070530008)资助的课题~~

摘　　要：利用基于密度泛函理论的第一性原理方法,系统研究了镧铱硅(La-Ir-Si)体系四种异构体的电子结构与成键机理.通过对能带结构、态密度的系统分析,发现:La-Ir-Si体系的超导属性与该体系中过渡元素Ir-d态和Si-p态的p-d轨道耦合强度有关.为了定量描述p-d轨道耦合的强度,采用了分子中的原子方法,针对La-Ir-Si体系成键过程中的电荷迁移进行了定量的分析,结果表明,超导的转变温度与体系中Ir原子basin中的电荷量成近线性关系.Using first-principles method, we studied the electronic structure and the bonding mechanism of La-Ir-Si materials. The results of the band structure and the density of the states indicated that the superconducting property of the La-Ir-Si system is determined by the p-d coupling strength between the transition element Ir-d and Si-p states of the material. In order to quantitatively describe the p-d coupling strength, we calculated the charge transfer during the bond process of the materials using the atom-in-molecule method. The results revealed that the superconducting transition temperature T_C is linerly proportional to the atomic basin charges of Ir.

关 键 词：La-Ir-Si 电子结构 超导属性 第一原理 

分 类 号：O481[理学—固体物理]