Study of ferromagnetism, spin-polarization, thermoelectrics and thermodynamics of layered perovskite Ba2FeMnO6 under pressure and temperature

A systematic evaluation of experimentally studied prototypical magnetic, Fm-3m (225) structured double perovskite Ba2FeMnO6 has been explored first time theoritically to investigate the electronic structure, magnetic, thermoelectric and thermodynamic properties. The optimized lattice constant by structural optimization is found to be consistent and in rational accord with the experimental lattice constant. The magnetic interactions were taken into consideration, among which ferromagnetic configuration was found stable. Band structure is predicted using the more sophisticated GGA + Hubbard model, where we find density of states feature half-metallic nature with a direct energy band gap of 3 eV. In addition, semi-classical Boltzmann theory for heat transport is used to check the applicability of the material for thermoelectric applications. Remarkably, thermoelectric Seebeck coefficient as well as spin resolved band structures, reflects the majority of p-type conduction of charge carriers as heat transporters. The conductivity due to phonon lattice vibrations show a decresing trend along the selected range of temperature. Also, complete and precise description of thermo-physical behavior of the vital quantities like Debye temperature, thermal expansion, Grüneisen parameter and specific heat were examined to check its thermodynamical stability against temperature and pressure variation. •Perfect half-metallic in nature.•Ferromagnetic in nature.•Descent thermoelectric response with decaying lattice thermal conductivity.•Thermodynamically stable.