Local structure, electrical and magnetic properties of Fe-doped Sr2(Ni,Mo)O6 double perovskite

Double perovskite material of 10 mol% Fe-doped Sr2(Ni,Mo)O6 was prepared by solid-state reaction. The NiMoO4 precursor was first synthesized as a starting material with calcination temperature at 1100 °C in air. Effects of FeO, Fe2O3 and Fe3O4 dopant on phase formation, morphology, electrical and magnetic properties of the specimens were investigated and discussed. The XRD technique was used to analyze the phase formation of the samples. It can be clearly seen that phase formation of pure Sr2(Ni,Mo)O6 indicated the cubic phase structure, while the tetragonal phase was found with FeO, Fe2O3 and Fe3O4 dopant. All XANES spectra were collected at the ambient temperature and atmospheric pressure. The result demonstrated that the oxidation state of Fe is 3+, indicating the occurrence of γ-Fe2O3 phase for all samples. In addition, the room temperature ferroelectric and ferromagnetic properties were determined using a simple Sawyer-Tower circuit (at fixed measuring frequency of 50 Hz) and Vibrating Sample Magnetometer (VSM), respectively. The maximum ferroelectric and ferromagnetic properties were seen with Fe2O3 dopant. Interestingly, the ferroelectric and ferromagnetic properties of Sr2(Ni,Mo)0.9Fe0.1O6 ceramics were affected by iron oxide doping.