First-principles calculation of structural and elastic properties of Pd_3-xRh_xV alloys

来源期刊：中国有色金属学报(英文版)2011年第2期

论文作者：王桃芬 陈平 邓永和 唐璧玉

文章页码：388 - 394

关键词：Pd_3-xRh_xV合金; 第一性原理计算; 电子结构; 弹性性能

Key words：Pd_3-xRh_xV alloys; first-principle calculations; electronic structure; elastic properties

摘    要：利用第一性原理对Pd_3-xRh_xV合金的2种结构(L1₂和D0₂₂)的相对稳定性、电子特性以及弹性性能等方面进行研究。计算结果表明：随着铑含量的增加，L1₂和D0₂₂型结构的合金晶胞体积均减小，晶胞有一定程度的压缩。与Pd₃V相比，加入铑元素，有利于Pd_3？xRh_xV合金的2种结构的稳定，并且合金结构趋于从D0₂₂型转化为更加稳定的L1₂型。对合金电子结构(态密度)的计算和分析说明，随着铑的加入，在费米能级以下铑和钒的杂化作用越来越明显，进一步影响L1₂和D0₂₂结构的稳定性。还对Pd_3？xRh_xV合金的L1₂和D0₂₂结构的弹性常数，如体积模量(B)、剪切模量(G)、弹性模量(E)和泊松比(ν)等随着铑加入的变化规律进行计算和讨论。

Abstract: The structural stability, electronic and elastic properties of Pd_3-xRh_xV alloys with L1₂ and D0₂₂ structures were investigated theoretically by the first-principles calculations. The results reveal that with the increase of Rh content, the unit cell volume of Pd_3-xRh_xV alloys with L1₂ and D0₂₂ structures decreases, and the structure of Pd_3-xRh_xV alloys tends to transform from D0₂₂ to L1₂. The elastic parameters such as elastic constants, bulk modulus, shear modulus, elastic modulus, and Poisson ratio, were calculated and discussed in details. Electronic structures were also computed to reveal the underlying mechanism for the stability and elastic properties.