Journal of the American Ceramic Society, Vol.88, No.11, 3279-3282, 2005
Phase formation and magnetoresistance of double perovskite Sr2FeMoO6
Phase formation behaviors of double perovskite Sr2FeMoO6 (SFMO) derived from mechanical activation were investigated. Polycrystalline double perovskite SFMO of grain sizes in nanometer range were synthesized by heat treatment of the precursors derived from mechanical activation of SrO, Fe2O3, and MoO3 at temperatures in the range of 600 degrees-900 degrees C in flowing atmosphere of H-2/Ar. Mechanical activation at room temperature led to formation of SFMO at 700 degrees C, which is about 200 degrees C lower than what is required in the conventional solid state reaction. The magnetization of thus-derived SFMO increases with increasing heat-treatment temperature in the range of 700 degrees-900 degrees C. Similarly, its magnetoresistance ratio also increases with increasing heat-treatment temperature, which is accounted for by the elimination of insulating SrMoO4 impurity phase and enhancement in crystallinity of the double perovskite SFMO phase.