Investigating the Multifunctional Role of Sr2FeMnO6 Double Perovskite in Spintronic and Thermoelectric Properties

Abstract

Herein, the double-perovskite Sr2FeMnO6 is investigated using density functional theory to investigate its electronic, magnetic, thermoelectric, and thermodynamic properties. The Sr2FeMnO6 show the ferromagnetic phase stability with the formation energy of about −2.53 eV. Spin-polarized band structure and density of states (DOS) calculations, performed using the Perdew–Burke–Ernzerhof generalized gradient approximation (PBE-GGA) and modified Becke–Johnson (GGA + mBJ) methods, confirm a half-metallic nature. The system exhibits metallic behavior in the spin-up channel, whereas the low-spin counterpart demonstrates semiconducting characteristics with a bandgap of about 1.38 eV. A total magnetic moment of 7 μB per formula unit is observed, predominantly originating from Fe and Mn atoms, with induced magnetism in oxygen attributed to Mn-3d, Fe-3d, and O-2p orbital interactions. The thermoelectric behavior of the system is studied by employing the semiclassical Boltzmann theory-based BoltzTraP code for both spin channels, revealing zT values of 0.98 and 0.94 for spin-down and spin-up channels, respectively, with zT decreasing and the power factor increasing with temperature. These findings highlight Sr2FeMnO6 as a promising candidate for spintronics, spin dynamics, and energy-harvesting applications, offering insights into its multifunctional potential.