Comprehensive first-principles investigation of multifaceted properties of LiGaC half-Heusler alloy

Abstract

Abstract The focus of this work is to investigate the intrinsic properties, such as the electronic, dynamical, mechanical, optical, and thermoelectric properties of LiGaC half-Heusler alloy, implementing density functional theory (DFT) calculations as incorporated in the Quantum Espresso Code. The structural parameters and electronic band structures are consistent with those reported in the literature. The computed dynamical and elastic properties in this work establish the dynamical and mechanical stability of LiGaC. For the case of optical properties, the computed real and imaginary parts of the dielectric function manifest the anisotropic character of the material which is in agreement with the computed elastic properties. For the electronic thermoelectric properties calculated over different temperatures from 300 K to 1100 K as a function of chemical potential, it has been found that the Seebeck coefficient is maximum at 300 K (∼1766 μV K −1 at 0.013 eV), whereas, the electrical conductivity has a maximum value of 1.23 × 10 3 S m −1 at −0.17 eV and 1100 K. A maximum power factor of 0.0012 W mK −2 is obtained at −0.035 eV and 1100 K. The lattice thermal conductivity decreases with the increase in temperature. Overall, the thermoelectric performance of LiGaC improves with the rise in the temperature.