高压下Mg_(2)Ni合金结构稳定性和弹性性质的第一性原理研究  

First-principles calculation of structural stability and mechanical properties of Mg_(2)Ni alloy under high pressure

作　　者：肖雄 逯来玉[1] 饶梓楚 XIAO Xiong;LU Lai-Yu;RAO Zi-Chu(College of Physics and Electronic Engineering,Sichuan Normal University,Chengdu 610068,China)

机构地区：[1]四川师范大学物理与电子工程学院,成都610068

出　　处：《四川大学学报（自然科学版）》2024年第3期255-261,共7页Journal of Sichuan University(Natural Science Edition)

基　　金：国家自然科学基金(50952025);四川省大学生创新训练项目(S202310636137);四川师范大学科研项目(024-341055001)。

摘　　要：基于密度泛函理论的第一性原理,本文对不同压强下Mg_(2)Ni合金的晶格结构和力学性能进行了计算和分析.计算结果表明:在0~60 GPa范围内,Mg_(2)Ni的晶格常数和晶胞体积随压强增加而单调减小.Mg_(2)Ni的弹性常数C_(11)、C_(12)、C_(13)、C_(33)和C_(44)在0~35 GPa压强下满足稳定性判据,在40~60 GPa压强下不满足稳定性判据,表明机械性能不稳定.高压会增强Mg_(2)Ni的体模量B、杨氏模量Y、剪切模量G.Mg_(2)Ni的柯西压力、G/B和泊松比,均表明Mg_(2)Ni在0~5 GPa压强下表现出脆性,在7~35 GPa压强下表现出延展性.The lattice constants,cell volumes and Mechanical properties of Mg_(2)Ni alloy at different pressures were calculated and analyzed by the first-principles investigations.It was shown that lattice parameters and volume of Mg_(2)Ni decreased gradually with increased pressures in the range of 0~60 GPa,and the elastic constant C_(11),C_(12),C_(13),C_(33)and C_(44)of Mg_(2)Ni satisfied the stability criterion at 0~35 GPa pressure.The stability criterion was not satisfied at the pressure of 40~60 GPa,which suggest mechanical instability.The bulk modulus B,Young's modulus Y and shear modulus G of Mg_(2)Ni all increased with the increase of pressure,which meant good mechanical properties in high pressure environment.The Cauchy pressure,G/B and Poisson's ratio of Mg_(2)Ni showed that Mg_(2)Ni exhibited brittleness at pressure of 0~5 GPa and ductility at pressure of 7~35 GPa.

关 键 词：Mg_(2)Ni合金 力学性能 第一性原理 

分 类 号：O482[理学—固体物理]