Structural, mechanical, thermal, and optical properties of inverse-Heusler alloys Cr2CoZ (Z = Al, In): A first-principles investigation

Abstract First-principles explorations were carried out on the structural, mechanical, thermal, and optical properties of Cr2CoZ (Z = Al, In) inverse-Heuslers for the first time using density functional theory (DFT). The formation enthalpy and elastic constants (satisfied Born criteria) respectively ensured the thermodynamic and mechanical stability of both compounds. The dynamical stability of Cr2CoIn was also confirmed by the phonon dispersion curve. The compound Cr2CoAl switched from brittle to ductile when Al is replaced by In, which in turn enhanced its machinability for industrial applications. In addition, these compounds showed themselves to be anisotropic, and the anisotropy decreased when Al was replaced with In. The Debye temperature and thermal conductivity of Cr2CoAl were also reduced due to the replacement of Al by In, which made it promising thermal barrier coating (TBC) material. Moreover, the deeper optical insights revealed the potential applications of our compounds in numerous optoelectronic and electronic device applications.