Band structure, magneto-Seebeck and magnetoresistance at the para-to ferri-magnetic transition in the Sr2FeReO6 double perovskite

Ferrimagnetic double perovskite Sr2FeReO6 exhibits coupled magnetic and thermoelectric phenomena near its para–ferrimagnetic transition (TC ≈ 405 K). Density functional theory with spin–orbit coupling predicts a significant Re orbital moment (+0.32 μB), large anomalous Hall (33 Ω⁻¹ cm⁻¹) and Nernst conductivities. Experiments reveal positive magnetothermopower and negative magnetoresistance below TC, resulting in a +20 % power factor enhancement at 336 K. Discrepancies between calculated and measured anomalous conductivities are attributed to reduced spin polarization and structural disorder. The work highlights topological transport and magneto-thermoelectric coupling in Sr2FeReO6.