ZnS和MgS的高压相变和弹性性质

Phase transition and elastic properties of ZnS and MgS under high pressure

为了进一步研究ZnS和MgS晶体在高压下的B1和B3结构的晶体结构和弹性性质,利用第一性原理平面波赝势密度泛函理论并通过GGA近似,计算得到了高压下ZnS和MgS晶体B3到B1结构相变的相变压强和高压下的弹性系数(C11,C12,C44,B),结果发现两者相变压强是11.87和0.78 GPa,两者在不同结构的弹性系数(C11,C12,C44)与压强变化具有相同的趋势:C11>C12>C44;同时计算得到了两种物质在基态的结构常数,并将其与其他实验和理论计算的结果对比,发现符合得甚好.

In order to study further the crystal structure and elastic properties of ZnS and MgS crystals under high pressure,the phase transition pressure,elastic coefficients（C11,C12,C44） and bulk modulus（B） of two crystals under high pressures were calculated with first principle plane-wave pseudo-potential density functional theory method and through generalized gradient approximation（GGA）.The results reveal that the pressure of phase transition from B3 to B1 structure is 11.87 and 0.78 GPa for ZnS and MgS crystals,respectively.The elastic coefficients of two crystals under different structures exhibit the same variation tendency with increasing the pressure,that is,C11C12C44.In addition,the structural parameters of two crystals on the ground-state were calculated.It is found that the obtained results are in good agreement with the experimental data and other theoretical results.