DFT investigation of half-metallic, thermoelectric and optical properties of MCrTaM’ (M = Fe and Ru, M’ = Al, Ga, Si and Ge) quaternary-Heusler alloys

Abstract

Researchers are interested in Heusler alloys because of their potential technical significance and multifunctional applications. In this paper, a complete theoretical analysis is performed using density functional theory to investigate the structural, mechanical, electronic, magnetic, thermoelectric and optical properties of MCrTaM’ (M = Fe and Ru, M’ = Al, Ga, Si and Ge) alloys. The structural and electronic properties of MCrTaM’ (M = Fe, M’ = Al, Ga, Si and Ge), RuCrTaAl and RuCrTaGa alloys indicate that all the alloys exhibit ferromagnetic ground state. The spin-polarized electronic band structure calculation shows that all the alloys exhibit half-metallic ferromagnetism (HMF) at their equilibrium lattice constant, which is also confirmed by the integer total magnetic moment of 2.00 μ_B and 1.00 μ_B for MCrTaM’ (M = Fe, Ru, M’ = Al and Ga) and FeCrTaM’ (M’ = Si and Ge) alloys respectively. The FeCrTaAl alloy is suitable for low-temperature thermoelectric applications with a ZT of 0.88 at 300 K, while the FeCrTaSi and RuCrTaAl alloys are more appropriate for high-temperature thermoelectric applications with ZT values of 0.69 and 0.62 at 900 K respectively. Optical spectra show that absorption is in the IR to near-UV wavelength range. According to the findings, these alloys could be useful in spintronics, thermoelectric, and optoelectronics applications.