Characteristics of fine size Fe-Ni alloy powders directly prepared by spray pyrolysis

Fe-Ni alloy powders with composition of Fe0.25Ni0.75 were directly prepared by spray pyrolysis. The powders prepared at temperatures of 1200 and 1400 °C had peaks of pure Fe-Ni3 alloy phase. The alloy powders with a spherical shape and dense structure were prepared at a temperature of 1400 °C by melting the powders. The composition ratio of Fe and Ni components in the alloy powders prepared at a temperature of 1400 °C coincided well with that of the spray solution. The mean sizes of the alloy powders changed from 0.20 to 0.74 μm when the concentrations of the spray solution changed from 0.02 to 1 M. The alloy powders prepared from the spray solution with a concentration of 0.5M had a maximum saturation magnetization and minimum coercivity values as 96.95 emu g−1 and 34.67 Oe, respectively.