Ba掺杂Si笼状化合物结构和电子性质的研究  

Study on Structure and Electronic Properties on Ba Doped Si Clathrates

作　　者：费英[1] 郑岩[1] 

机构地区：[1]渤海大学物理系,锦州121013

出　　处：《人工晶体学报》2009年第5期1255-1260,1265,共7页Journal of Synthetic Crystals

摘　　要：利用第一性原理研究了Ba8Si46和Ba8Ag6Si40笼状化合物的电子性质。对于Ba8Si46,化合物中Ba原子5d轨道与Si原子3s,特别是3p轨道杂化,一方面导致了Ba8Si46在费米能级附近有很高的态密度,另一方面说明了笼内Ba原子和笼上Si原子之间存在耦合。对于Ba8Ag6Si40分析结果表明,由于Ag的5s轨道向Si的3p轨道转移电子,导致Ag与Si原子间成键趋向离子键。带结构显示这两种化合物具有弱金属特征,但Ba8Ag6Si40化合物与费米能级相交的带宽较大,预期这种化合物具有更好的导电性能。The population and density of states of electrons of Ba8Si46and Ba8Ag6Si40were analyzed in the paper. The Ba8Si46 results show Ba 6s electrons are transferred into the Ba 5d and Si 3p orbits. The sp3 hybridizations of framework Si make the compound posses stabile structure. For Ba8Ag6Si40,Ag 5s electrons are transferred into the Si 3p orbits.The Ag doping destroys sp3 hybridizations of framework Si. The bond between Ag and Si atoms tends to electrovalent bond. The band structures of Ba8Si46and Ba8Ag6Si40indicate that they are weak metal. Because the band width intersecting with Eermi level for Ba8Ag6Si40 is larger than Ba8Si46,Ba8Ag6Si40 compound has higher conductance than Ba8Si46.

关 键 词：笼状化合物 第一性原理 电子结构 稳定性 

分 类 号：O484[理学—固体物理]