Structural, high pressure and elastic properties of transition metal monocarbides: A FP-LAPW study

The structural, elastic and thermal properties of four transition metal monocarbides ScC, YC (group III), VC and NbC (group V) have been investigated using full potential linearized augmented plane wave (FP-LAPW) method within generalized gradient approximation (GGA) both at ambient and high pressure. We predict a B1 to B2 structural phase transition at 127.8 and 80.4 GPa for ScC and YC along with the volume collapse percentage of 7.6 and 8.4%, respectively. No phase transition is observed in case of VC and NbC up to pressure 400 and 360 GPa, respectively. The ground state properties such as equilibrium lattice constant (a0), bulk modulus (B) and its pressure derivative (B′) are determined and compared with available data. We have computed the elastic moduli and Debye temperature and report their variation as a function of pressure.

Graphical AbstractHigh pressure study of TMC compounds (TM=Sc, Y, V and Nb) have been performed using FP-LAPW method. Pressure induced phase transition from B1 to B2 has been observed for ScC and YC at 127.8 and 80.4 GPa. No phase transition has been observed for rest of the carbides up to pressure 360 GPa.We first time predicted the elastic constants for ScC and YC. Both the compounds show ductile behavior. The variation of Debye temperature with respect to pressure has been observed..Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► We have predicted first time a pressure induced structural phase transition for ScC and YC. ► We have predicted the elastic and thermal properties for ScC and YC. ► Group III TMCs are ductile in nature as compared to group V TMCs. ► We have investigated how the different number of d-electrons influences the elastic and thermal properties of TMCs.