Exploring the physical, magnetic, opto-spintronics and thermoelectric properties of Fe2ZrAs Heusler Alloy through DFT study

Abstract

In this work, we investigated the structural, thermoelectric, optical, and magnetic properties of the Fe₂ZrAs Heusler alloy using ab initio calculations based on density functional theory, the full-potential linearised augmented plane wave (FP-LAPW) method, and semi-classical Boltzmann transport theory. The calculated total spin moment is found to be approximately 1.0 μB at the equilibrium lattice constant, which remarkably agrees with the Slater-Pauling rule. In the spin-down channel, the Fe₂ZrAs compound exhibits direct semiconductor behaviour, and at the Γ -Γ symmetry point, a direct band gap of roughly 0.477 eV has been observed. A halfmetallic bandgap of 0.379 (eV) has also been calculated. Thermoelectric characteristics between 100 and 1200 K were computed. The maximum value of Seebeck coefficient S is 950 μV/k μV K⁻¹ at 300 K. In a similar vein, S slightly decreases to 250 μV K⁻¹ at 1200 K. The n-type doped compound has a higher thermal conductivity than the p-type doped compound. Thermal conductivity increased in direct proportion to chemical potential. Optical calculations demonstrated an imaginary dielectric function threshold for the spin-down channel. Due to the free-electron effects, spin-dependent optical calculations revealed that the intraband contributions only had an impact on the spin-up optical spectra. Overall, the findings supported the idea that the intraband contribution played a primary role in the optical spectra of low-energy visible and infrared light.