Effect of cation exchange on structural, electronic, magnetic and transport properties of Ba2MReO6 (M = In, Gd)

•Physical properties of Ba2MReO6 (M = In, Gd) via density functional theory.•Both the Ba2MReO6 compounds were found as mechanical and thermodynamically stable.•The electrical behavior of both the perovskites was found to be half-metallic.•Total magnetic moments of both the compounds pose strong ferromagnetism in them.•The spin has major influence on thermoelectric properties. Insight on the structural, electronic, magnetic and thermoelectric properties of Ba2MReO6 (M = In, Gd) compounds has been taken into the examination under density functional theory approach. Formation energy (ΔHf) calculation resulted in −53.60 eV (Ba2InReO6) and −58.09 eV (Ba2GdReO6) which specify that the given compounds are thermodynamically stable. Tolerance factors (τ) of about a unity (0.9) for both materials clarify their cubic stability while high values of cohesive energies have explored strong bonds between the constituent atoms. Structural optimizations support the ferromagnetic stability of both materials with the lattice constants values of 8.20 Å (Ba2InReO6) and 8.37 Å (Ba2GdReO6). The spin-based density of states calculations described the half metallicity in both the compounds, where, in spin down state, the semiconducting nature with direct band gap of 2.94 eV and 2.74 eV for Ba2InReO6 and Ba2GdReO6 respectively was evaluated from band structure calculation. Total magnetic moments equal to 2.00 μB (Ba2InReO6) and 9.00 μB (Ba2GdReO6) pose strong ferromagnetism in them. The calculated thermoelectric coefficients support the high electrical and low electronic thermal conductivities and suggest the efficient functioning of the studied compounds at wide range of temperatures (200 K-800 K). Also, high values of Seebeck coefficient (S) and figure of merit (ZT) pretenses their applications for thermoelectric conversions. The overall properties via these first principle calculations opens the possibilities of Ba2MReO6 for their future experimental perceptions with exciting applications in spintronics and green power generation.