Phononic, electronic, elastic and thermodynamic properties of ScSi under high pressure via first principles calculations

Abstract

In present paper, we perform first principles based on density functional theory to investigate the effect of high pressure on phononic, electronic, elastic and thermodynamic properties of ScSi. It is found that phonon dispersion curve of ScSi has no virtual frequency within a given pressure range from 0 GPa to 35 GPa, indicating that the material is thermodynamically stable. When a given pressure is larger than 40 GPa, ScSi is thermodynamically instable and will occurs phase transition. Band structure and density of states confirm that ScSi is metallic. The elastic constant Cij increases with increasing pressure, and meets the Born�s criterion, which shows that ScSi possesses mechanical stability. Meanwhile, the ductility and toughness of material increase with increasing pressure, which is very conducive to industrial applications. In addition, Debye temperature and sound velocity increase linearly with pressures, indicating that appropriate pressure can improve elasticity, hardness, melting point and specific heat.