First-principles study of thermodynamic study of transition Metal Silicides TMSi (TM = V, Cr, Co)

Based on first-principles calculations, this study systematically investigates the crystal structures, electronic band structures, phonon properties, elastic constants, and thermal transport properties of B20-type TMSi compounds (TM = V, Cr, Co). Structural optimizations and property simulations were conducted using the CASTEP module in Materials Studio. The results indicate that all three materials possess both dynamical and mechanical stability and exhibit metallic behavior with good electrical conductivity. The absence of imaginary frequencies in the phonon spectra confirms their thermodynamic stability. Mechanical parameters such as bulk modulus, shear modulus, and Young’s modulus exhibit compositional dependence; CoSi shows a certain degree of ductility, whereas VSi appears relatively brittle. The lattice thermal conductivities, calculated using the Slack model, follow the order VSi > CrSi > CoSi, which is significantly influenced by phonon scattering and mass perturbation. These findings provide insight into the intrinsic thermal transport characteristics of metallic silicides and their potential for applications where efficient heat conduction is required.