Multifunctional Properties of FeMnScAl Quaternary Heusler Alloy: Insights into Spintronics, Photovoltaics, and Thermoelectric Applications

Abstract

The increasing demand for efficient and low-cost multifunctional materials in the fields of spintronics, solar cell technology, and thermoelectric applications is a big challenge. The exceptional electronic and magnetic properties of Heusler alloys have made them promising candidates, allowing for fine-tuning for specific applications. This study investigates the elastic, structural, electronic, magnetic, optical, and thermoelectric properties of the FeMnScAl quaternary Heusler alloy using density functional theory with the full-potential linearized augmented plane wave method via Wien2K software and BoltzTraP for thermoelectric analysis. Results confirm that FeMnScAl is thermodynamically and mechanically stable, as evidenced by its negative formation energy and elastic constants meeting the stability criteria, with an optimized lattice parameter of 6.116 Å. Density of states and band structure analysis reveal its half-metallic character. The calculated magnetic moment of 3.00 μB follows the Slater-Pauling rule and stands for ferromagnetism. FeMnScAl also possesses special optical properties, such as a narrow band gap of 0.677 eV, a high refractive index (2.63 < n(ω) < 3.77), low reflectivity in the visible region, strong UV absorption, and superluminal effects. This provides facilities for efficient light trapping and hence forms a candidate material to be used in photovoltaic applications. Finally, the thermoelectric properties reveal possible low-cost devices since FeMnScAl has shown a ZT value of 0.628 along with a high Seebeck coefficient of 196 μVK^–1 at room temperature. With these results, it seems that FeMnScAl could be used in spintronic, thermoelectric, and green energy technologies. Further experiments are needed to confirm the efficacy of this material.