NiAl和Cr材料中H原子间隙的第一性原理计算  

First-principles study of hydrogen atom in interstitial sites of NiAl and Cr

作　　者：尚家香[1] 于潭波[1] 

机构地区：[1]北京航空航天大学材料科学与工程学院,北京100191

出　　处：《物理学报》2009年第2期1179-1184,共6页Acta Physica Sinica

基　　金：全国优秀博士学位论文作者专项基金(批准号:200334)资助的课题~~

摘　　要：通过第一性原理赝势平面波方法研究了氢原子在B2-NiAl和Cr合金中的占位以及对键合性质的影响.H在NiAl的富Al和富Ni八面体间隙杂质形成能分别为-2.365和-2.022eV,而在四面体间隙不稳定.H在Cr的八面体和四面体间隙的杂质形成能分别为-2.344和-2.605eV.H在NiAl中的最稳定位置为富Al八面体间隙,而在Cr中的最稳定位置是四面体间隙.可以预期H在B2-NiAl/Cr体系中主要占据Cr的四面体间隙位置.通过分析原子结构、电荷集居数、价电荷密度以及态密度,讨论了H对B2-NiAl和Cr合金原子结构和电子结构的影响.The site occupancy of hydrogen atom in B2-NiAl and Cr alloys and its effect on NiAl and Cr were studied by the first-principle plane-wave pseudopotential method. For NiAl system the impurity formation energies of hydrogen are -2.365 and -2.022eV in the Al-rich octahedral site and Ni-rich octahedral site, respectively, while it is unstable in a tetrahedral site. For Cr system, the impurity formation energies of hydrogen are -2.344 and -2.605eV in the octahedral site and tetrahedral site, respectively. The most stable site of hydrogen is the Al-rich octahedral site in NiAl and the tetrahedral site in Cr. It is most probable that hydrogen mainly occupies the interstitial site in NiAl/Cr alloy. By analysis of the atomic structure, electron population, valence electron density and the density of states, the effects of hydrogen atom on atomic structure and electronic structure of NiAl and Cr alloys are discussed.

关 键 词：NiAl/Cr双相合金 H原子 第一性原理 

分 类 号：O481[理学—固体物理]