Physical properties of MAX phase Zr2PbC under pressure: Investigation via DFT scheme

This study investigates the physical properties of Zr2PbC under pressure using DFT. The lattice constants drop linearly from a = 3.41 to 2.97 Å and c = 14.96 to 13.60 Å with increasing pressure ranging from 0 to 100 GPA. The negative formation enthalpy confirms the thermodynamic stability the pressurized phases. Moreover, the Born stability factors are satisfied by elastic constants, ensuring the mechanical stability of pressurized and non-pressurized Zr2PbC. The compound switches from brittle to ductile and the maximum ductility is observed at 20 GPa pressure, as the Pugh's ratio decreases from 0.67 to 0.37 and Poisson's ratio increases from 0.23 to 0.34. The anisotropy becomes more intensive with pressure. Although the band structure has been tuned under pressure, the metallic nature is retained. The co-existence of covalent, metallic, and ionic bonding is observed in Zr2PbC. The optical functions suggest the potential applications of this compound in various sectors. •Decreasing affinity of lattice parameters reflects the effects of pressure.•The compound switches from brittle to ductile under pressure.•The anisotropy becomes more intensive with increasing pressure.•Band structure is tuned by the application of pressure.•Optical properties demonstrate several potential applications of Zr2PbC.