Synthesis by oxalic (citric) route and electrical and magnetic characterization of Sr2FeMoO6 perovskite

Sr2FeMoO6 was synthesizes by soft chemistry route using citric and/or oxalic acid as complexing agents. This method provides good compositional control with promising results as a base for further improvements. The material shows complex temperature- and field- (magnitude and orientation) dependent electro-magnetic behavior as probed by magnetic and transport measurements. The zero-field cooling curves of magnetization versus temperature taken at different magnetic fields, show two temperature regions separated by a transition temperature TcupsZFC. When H   increases, TcupsZFCvalues decrease. At 5 K and 5 T the saturation moment is 3.55 μB per formula unit, and the coercitive force is 0.021 T. The relative value of the magnetoresistive effect (i.e. 100 (ρH−ρ0)/ρH, %, with ρ being resistivity) at 5 K is 68% and 36% when applied field H is parallel and perpendicular the measuring current I, respectively. The results are discussed in relation to magnetic sublattices and the interaction that produces anti-site defects and spin-dependent electron anisotropy.