过渡金属元素X(X=Ni,Ti,V)掺杂对Mg17Al12合金结构的影响

Effects of Transition Metal X (X=Ni, Ti, V) Doping on Mg17Al12 Alloy

关键词:  密度泛函理论  几何结构  态密度  Mg₁₇Al₁₂

Key words:  density functional theory  geometry structure  density of states  Mg₁₇Al₁₂

摘要:

[目的]提高镁铝(Mg-Al)合金材料的储氢性能。[方法]基于密度泛函理论的平面波赝势方法,对过渡金属元素X (X=Ni,Ti,V)掺杂Mg₁₇Al₁₂合金体系的生成焓、电子结构、态密度、电荷密度等进行理论计算研究。[结果]过渡金属元素X替代合金中Mg元素的能量较低,其中Ni的掺杂性能较好;Ni的加入改善了Mg₁₇Al₁₂的储氢性能。且随着Ni浓度的升高,Mg₁₇Al₁₂合金的体积逐渐减小,总态密度峰值依次增大。[结论]过渡金属元素X (X=Ni,Ti,V)的掺杂可使镁铝合金的稳定性得到提升,与实验结果相符。

Abstract:

[Objective] To improve the hydrogen storage property of Mg-Al alloy material.[Methods] Based on the density functional theory method of plane wave potential, the formation enthalpy, electron structure, density of states, and charge density of Mg₁₇Al₁₂ doping with transition metal X(X=Ni, Ti, V) systems were investigated.[Results] The results show that the energy of Mg element in the substitution metal of the transition metal element X is lower, and the doping property of Ni is better.The addition of Ni improves the hydrogen storage performance of Mg₁₇Al₁₂.With the increase of Ni concentration, the volume of Mg₁₇Al₁₂ alloy decreases and the peak value of total density increases in turn.[Conclusion] The doping of transition metal element X(X=Ni, Ti, V) enhances the stability of Mg-Al alloy, which is consistent with the experimental results.