Sr₂Fe₁₊ₓRe₁₋ₓO₆ double perovskites: magnetoresistance and (magneto)thermopower

Polycrystalline Sr₂Fe₁₊ₓRe₁₋ₓO₆ samples have been synthesized and structurally characterized by X-ray powder diffraction, transmission electron microscopy and X-ray absorption spectroscopy. Resistivity strongly increases with x, but a large and negative magnetoresistance persists up to x = 0.33. This is discussed considering the charge delocalization in iron and rhenium t₂g orbitals.