First-principles Investigation of Elastic Anisotropy and Thermal Transport Property of Transition Metal Monosilicides CrSi, TiSi, and ZrSi under Pressure

In this paper, the influence of pressure on the elastic anisotropy and thermodynamics of CrSi, TiSi, and ZrSi monosilicides are investigated by the first-principles method. Those three alloys have elastic anisotropy, and the degree of anisotropy meets the relationships TiSi > ZrSi > CrSi. In addition, all the elastic anisotropy is enhanced with the increasing pressures. The melting point and Vicker’s hardness are investigated, and the results show that CrSi, TiSi, and ZrSi alloys may be promising high-temperature and hard materials. Furthermore, the lattice thermal conductivity is calculated by Slack’s equation only using the elastic properties. The pressure-dependent Debye temperature, Grüneisen parameter, and lattice thermal conductivity are systematically analyzed. Debye temperature enhances with increasing pressure while the Grüneisen parameter reduces with pressure. Consequently, the lattice thermal conductivity can be enhanced by the pressure, which benefits heat transportation. The calculation reveals that the pressure can effectively control the elastic anisotropy, Deby temperature, Grüneisen parameter, and the lattice thermal conductivity, which is useful for its practical application in industry.