The disorder is induced by S doping at O-sites in double perovskite Sr2FeMoO6 compound

We have investigated the crystal, structural and physical properties of polycrystalline Sr2FeMoO5.5S0.5. The structure of this compound is assigned to the tetragonal system with space group I4/mmm and the Rietveld refinement results show that there exist about 23% of anti-sites. Thermal magnetization demonstrates the Curie temperature to be higher than 300 K. Thermal magnetization and isothermal magnetic measurements show a magnetic or structural phase transition at around 190 K. The saturation moment obtained from Rietveld refinement results and isothermal magnetic curve are 2.21 and 2.04 μB (78 K), respectively. The evident magnetoresistance is observed under 0.5 and 1.0 T magnetic fields in cooling and warming modes, respectively. Variation of the coefficients in T1/2, T2 and T3/2 terms follows the residual resistivity in both modes. The residual resistivity decreases with magnetic field. Under 0 T magnetic fields the coefficient in T2 term is inversely proportional to spin-wave stiffness constant, D, in both modes.