Record saturation magnetization, Curie temperature, and magnetoresistance in Sr2FeMoO6 double perovskite synthesized by wet-chemistry techniques

Wet-chemistry techniques, involving the previous elaboration of reactive citrate precursors, have been used to prepare, Sr2FeMoO6 double perovskite in polycrystalline form. This material has been characterized by x-ray and neutron powder diffraction, magnetic, and magnetotransport measurements. It exhibits a ferromagnetic Curie temperature of 416 K, and an almost complete Fe/Mo ordering at the B sublattice of the perovskite, accounting for the high saturation magnetization at 5 K, of 3.97 mu(B) per formula unit. The magnetoresistance (MR) is higher than 45% at 5 K, for H=9 T, and the low-field MR is as high as 6.5% at room temperature for H=0.3 T. These excellent features are a consequence of the good homogeneity of the samples, prepared from precursors where a perfect cationic mixing at atomic level is promoted. (C) 2004 American Institute of Physics.