Mechanically activated synthesis and magnetoresistive behavior of double perovskite Sr2FeMoO6

Abstract

Double perovskite Sr2FeMoO6 of single phase was realized at 700 degree C in flowing 5% H2/Ar, which is about 200 degree C lower than what is required in the conventional solid state reaction. By changing the starting material from MoO3 to MoO2, Sr2FeMoO6 was successfully synthesized in air by mechanical activation for the first time. Magnetization and magnetoresistance (MR) of MoO2-based Sr2FeMoO6 increases when increasing mechanical activation time. B-site order in Sr2FeMoO6 was systematically enhanced by increasing sintering temperature in the range of 800 degree C to 1100 degree C. Magnetization as well as MR is significantly enhanced by high temperature sintering. Polycrystalline Sr2(Fe(1-x)Nix)MoO6 (x=0.0,0.05,0.10,0.15,0.20) was successfully synthesized via mechanical activation. The long-range order parameter is significantly enhanced by Ni doping. Ni-doped Sr2FeMoO6 exhibits a linearly increasing magnetization and Curie temperature with the increasing level of Ni doping.