SYNTHESIS, STRUCTURAL AND MAGNETIC PROPERTIES OF DOUBLE PEROVSKITES Sr₂CrWO₆

The double perovskite (Sr₂CrWO₆) has been prepared in polycrystalline state by solid state reaction. At room temperature, the crystal structure is cubic (space group: Fm3m) with lattice parameter of 7.8200(2) (Å). Both ρ(H=0) and ρ(H=5T) show a semiconductor-like behavior over the whole temperature range up to 5 K. The highest MR(magnetoresistance) value of 55% (H=5T) was observed at 25 K. The valence state of Cr was determined by the X-ray absorption spectroscopy at Cr-L edge. The results, compared to the standard sample, show that the valence state of Cr is 3+.