Structural and magnetic investigation of Ba2(Fe,Re1-xwx)2O6 (0≤x≤0.5)

The double-perovskite series Ba2(Fe,Re1-xWx)2O6, where x=0, 0.2, 0.4 and 0.5, have been prepared as pure powders by a conventional solid-state reaction and studied by X-ray powder diffraction and magnetization measurements. X-ray powder diffraction has been carried out at different temperatures (between 90 and 300 K) to study structural and magnetic properties of Ba2(Fe,Re)2O6. Rietveld analysis of X-ray diffraction patterns show a partial disorder of Re/W and Fe on the B sites of the double-perovskite, which plays a dominant role in the structural and magnetic properties of these compounds. The symmetry is cubic (Fm3-barm) for all samples, and no phase transition was detected for Ba2(Fe,Re)2O6 between 95 K and room temperature. The magnetic properties of these series are remarkable: TC goes to a maximum reaching 338 K for x=0.2, with a spontaneous moment lower than the theoretical value