Unveiling the Exceptional Half‐Metallic, Optoelectronic, and Thermoelectric Properties of FeMnScGa: A DFT Study

Abstract

ABSTRACT Efficient and economical multifunctional materials are of interest for applications in spintronics and magneto‐optic devices. Heusler compounds, known for their specific electronic and magnetic properties, are promising candidates because they can be tuned for specific applications. This computational study examines the elastic, structural, electronic, magnetic, and optical properties of FeMnScGa, a quaternary Heusler compound, aiming to advance its use in spintronics and green electronics. First‐principles calculations were performed using Wien2k software, implementing the full‐potential linearized augmented plane wave method (FP‐LAPW), based on density functional theory (DFT). While the compound has a negative formation energy and obeys the Cauchy criteria on elastic constants, the presence of imaginary frequencies suggests that the structure may distort to a lower symmetry. The material exhibits thermal properties, as indicated by a Debye temperature of 414 K and an estimated melting point of ∼1600 ± 300 K. Furthermore, with an optimized lattice parameter of ∼6.12 Å, the analysis of the density of states (DOS) and band structure reveals the material's half‐metallic nature. The compound shows ferromagnetic behavior, with a magnetic moment of 3.00 μB that aligns with the Slater–Pauling rule. Furthermore, FeMnScGa has a 0.442 eV narrow band gap and high UV absorption, with the refractive index being 2.6 to 4.2 in the 1.67–3.3 eV visible spectral range. Such properties make FeMnScGa a material for optoelectronic applications. FeMnScGa exhibits thermoelectric performance, as shown by Seebeck coefficients reaching 40 µV/K, power factors of 4.58 × 10 1 1 W/(m·K 2 ), and ZT values of ∼0.061 at 600 K, making it a promising candidate for energy harvesting and cooling systems. In light of these computational results, FeMnScGa appears to be a promising candidate for spintronic and green energy applications. Confirmation of its effectiveness requires additional experimental studies.