First-principle study of structural, electronic, thermoelectric and vibrational properties of Co₂-based Weyl semimetal VCo₂Al

Abstract

The class of semimetals has emerged as upcoming future devices due to their technological efficient applications. The distinctive component in semimetals is the simultaneous manipulation of spin states along with electronic states that has prompted the discovery of spin ordering at Fermi level. The current investigation is first-principle approach to compute structural, electronic, thermoelectric and vibrational properties of VCo₂Al. The systematic and detailed theoretical investigation based on density functional theory in combination with Boltzmann transport theory has been done for the first time. The structural properties namely lattice constant, bulk modulus and pressure derivative of bulk modulus have been calculated, revealing that VCo₂Al gets stiffer on applying pressure. The plotted electronic band structure shows band dispersion at two discrete points at Fermi level specifying VCo₂Al to be Weyl semimetal. The joint analysis of electronic band structure and plotted density of states affirms the band dispersion and presence of Weyl electrons at Fermi level. The present investigation purposes VCo₂Al as an excellent n-type high temperature thermoelectric material having power factor of 184.3 × 10¹⁴ µW cm⁻¹ K⁻² s⁻¹ at 800 K. The vibrational properties calculated within the framework of density functional perturbation theory uncover the dynamic stability of VCo₂Al. The computed physical properties from these calculations would create new frontiers of experimental work for further realization of innovative applications.