摘要
基于密度泛函理论框架下的第一性原理离散变分(DV)和DMol方法研究了4d过渡金属元素在γ-TiAl中的择优占位行为及其Nb和Mo的合金化效应.转移能的计算结果表明Y,Zr,Nb,Mo在γ-TiAl中有Ti占位倾向,而Tc,Ru,Rh和Pb则表现为Al占位倾向.通过对差分电荷密度、Mulliken轨道集居数以及态密度的分析表明Nb和Mo可以提高杂质元素与其近邻基体元素之间的相互作用和相应原子之间的键合强度,导致较强的固溶强化效应.
The site substitution behavior of the 4d transition elements and the alloying effect of Nb and Mo have been studied using the first-principles discrete variational （DV） and DMol method within the framework of the density-functional theory. The transfer energy calculation indicates that Y, Zr, Nb, and Mo show the tendency to occupy Ti sites while Tc, Ru, Rh, and Pb have the tendency to occupy Al sites in γ-TiAl. In addition, the alloying effect of Nb and Mo on the electronic structure of γ-TiAl is also studied. It was found that Nb and Mo give rise to strong interaction and charge transfer with the neighboring host atoms of TiAl, resulting in a strong solution strengthening effect.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2007年第5期2838-2844,共7页
Acta Physica Sinica
基金
国家重点基础研究发展规划项目(批准号:2006CB605102)
国家自然科学基金(批准号:90306016)资助的课题~~
关键词
密度泛函理论
第一性原理
电子结构
density-functional theory, first-principles, electronic structure
