First principle study of physical aspect and role of 3d/4d electrons in ferromagnetism in Ba2XWO6 (X = Fe, Mn, Co, Ni) for spintronic applications

Abstract

A recent article systematically investigated the electronic behavior, Curie temperature, spin polarization, magnetic, thermoelectric, mechanical, and thermodynamic aspects of Ba₂XWO₆ (X = Fe, Mn, Co, Ni) by the use of Wien2K and BoltzTraP codes. The comparatively larger energy release in ferromagnetic states than in antiferromagnetic states (A-, C-, G-) ensures the stability of FM states. Moreover, the tolerance factor, formation energy, and the phonon dispersion band structures confirm the ferromagnetic states' structural, thermodynamic, and dynamic stability. The empirical relation of Heisenberg and band structure analysis measures the ferromagnetism above room temperature and 100 % spin polarization (SP = 1.0). Furthermore, the hybridization of individual density of atomic states, double exchange, and exchange are also briefly focused on the nature of ferromagnetism and the exchange function of 3d/4d electrons' spin. Ferromagnetism is caused by the exchange of electrons, not by magnetic ion clustering, which has been revealed by shifting the magnetic moment from X (5.0 to 2.0) μ_B and W sites to Ba and O sites. In addition, the effect of thermal conductivity, lattice vibration, Seebeck coefficient, and electrical conductivity on the spin degree of freedom of electrons has been explored for both spin (↑) and spin (↓) arrangements. The power factor and figure of merit (1.58, 1.37, 1.34, 1.33) calculate the performance of these DPs for energy harvesting. Finally, the elastic constants satisfy the Born criteria and show a ductile nature. The large melting and Debye temperature, hardness, and minimum lattice thermal conductivity have also increased the importance of these materials for spintronic applications.