ANiN(A=Li,Na,Mg,Ca)的结构、热力学、弹性和电子性质的第一性原理研究

三元过渡金属氮化物ANiN(A=Li,Na,Mg,Ca)是潜在的可充放电池的电极材料.物理性质,比如热稳定性、电子能隙以及弹性稳定性等,对于这些材料的电池应用都是非常重要的.本文使用第一原理方法,对比研究了 ANiN这些材料的结构、动力学、弹性和电子结构性质.对状态方程和声子谱的计算被用来确定体系的稳定结构.对最稳定结...

Structural,Dynamic,Elastic and Electronic Properties of ANiN(A=Li,Na,Mg,Ca):First-Principles Calculations

Ternary transition metal nitrides ANiN(A=Li,Na,Mg,Ca)are potential electrode materials for rechargeable batter-ies.The physical properties,such as the thermodynamic stability,the electronic band gap as well as the elastic stability,are impor-tant for their battery applications.Here,comparative studies are performed for the structural,dynamic,elastic and electronic proper-ties of ANiN by the first-principles method.The calculations on the cohesive energy versus unit-cell volume and phonon spectra are employed to determine the most stable structures of ANiN.The calculated elastic constants of the most stable structures indicate that the Born-Huang criterion for the elastic stability can all be satisfied,showing the elastic stability of the materials.The electronic structures calculations suggest that LiNiN and CaNiN are half-metals,MgNiN is magnetic metal,while NaNiN is a common metal.The magnetization of the materials is understood by the Stoner theory.Furthermore,the charge density plots have been used to illus-trate the bonding between Ni and N atoms,which is mainly ionic mixed with covalent.