Elastic metastability, lattice compressibility and thermodynamic properties of (Cr0.5V0.5)2GeC from first-principles

The elastic and thermodynamic properties of (Cr0.5V0.5)2GeC under high pressure and temperature are predicted by first-principles. Our calculated c axis is always stiffer than a axis between 0 and 800 GPa, completely consistent with the sequence of the axial bulk moduli. The structural metastability between 300 and 600 GPa has been observed from the elastic softening (C11–C12) but not from C44. Of the three shear components (GV, GR, GH) investigations at higher pressure, only GR estimation behaves more similarities with (C11–C12), and no any shear component even GV has presented certain similarities with C44. The effects of the pressure and temperature on the bonding nature and thermodynamic properties are also studied.

► The elastic and thermodynamic properties of (Cr0.5V0.5)2GeC under high pressure and temperature are predicted by first-principles.
► The calculated c axis is always stiffer than the a axis, completely evidenced by the axial bulk modulus.
► The structural metastability within 300–600 GPa has been observed resulting from (C11–C12) other than C44.
► The shear components (GV, GR, GH) investigations predicted that GR behaves more similarities with that of (C11–C12).
► The effects of the pressure and temperature on the bonding nature and thermodynamic properties are also studied.