Study of half metallic ferromagnetism, Curie temperature, and thermoelectric aspects of double perovskite oxides Ba2XMoO6 (X = Cr, Mn, Fe, Co) for spintronic applications

Abstract

Spintronics is a cutting-edge technology that manipulates both the spin and charge of electrons to control the behaviour of multifunctional devices. Here in the current paper, the half-metallic ferromagnetism, electronic properties, and influence of transport parameters on the magnetic behaviour of double perovskite oxides Ba₂XMoO₆ (X = Cr, Mn, Fe, Co) are addressed comprehensively by Wien2k and Boltz Trap codes. The ferromagnetic (FM) state exhibits higher optimized energy compared to antiferromagnetic (AFM) and paramagnetic (PM) states, showing enhanced stability. The negative formation energy (−2.65, −2.62, −2.49, −2.46) eV further confirms the thermodynamic stability of these materials. The spin polarization density and magnetic moments (4.0, 5.0, 4.0, 3.0)μ_B collectively validate the 100 % spin polarization. The Heisenberg model ensures the Curie temperature (340, 331, 325, 313)K at room temperature. The band structures exhibit discrete metallic and insulating characteristics for spin-up and spin-down configurations, thereby consolidating half-metallic ferromagnetism in these materials. The double exchange mechanism, hybridization p-d states, and associated exchange constants influence the exchange splitting energies, which eventually elaborate the function and nature of the spin of electrons that establish ferromagnetism in the studied system. The analysis of the Seebeck coefficient and thermal and electrical conductivities have explained the influence of transport properties on the spin functionality of the electrons. Additionally, the power factor has been reported to assess their thermoelectric performance. The stable structures, above-room temperature ferromagnetism, and ultralow lattice thermal conductivity increase their importance for spintronics.