Cation distribution and magnetism study in the Mg0.5Ni0.5NdxFe2-xO4(x=0, 0.01, 0.03, 0.05) spinel system based on Mössbauer spectroscopy

Abstract

This study successfully synthesized Mg_0.5Ni_0.5Fe_2-xNd_xO₄(x = 0, 0.01, 0.03, 0.05) spinel ferrites using the sol-gel method. X-ray diffraction analysis revealed that doping with Nd³⁺ enhanced lattice distortion, and a secondary NdFeO₃ phase emerged at higher concentrations. Mössbauer spectroscopy analysis revealed that Nd³⁺ doping modified the distribution of metal cations within the samples and yielded theoretical values for the samples' magnetic moments. Magnetic analysis indicated that magnetic parameters, including saturation magnetization, remanence, and coercivity, displayed irregular variations with increasing Nd³⁺ concentration, peaking at x = 0.03, while the presence of the NdFeO₃ secondary phase induced abnormal changes. These irregular variations may be attributed to the combined effects of microscopic magnetic mechanisms regulating the sample's magnetic response, such as lattice structure, metal cation distribution, the Yafet-Kittel spin canting effect, and the presence of the NdFeO₃ secondary phase.