Adjustable ferrite amount for various characteristics of Ni0.5Cd0.5Fe2O4 nanoparticles incorporated in a SiO2 matrix

The (Ni_0.5Cd_0.5Fe₂O₄)_x(SiO₂)_100‒x (x = 0%‒100%) samples were synthesized through sol‒gel technique followed by the study of the evolution of crystalline phases at different temperatures. For the samples containing ferrite, the X-ray diffraction indicated the development of ferrite and SiO₂ matrix and displayed single, low crystallized ferrite at low temperatures and well-crystallized ferrite attended by Fe₂O₃ and SiO₂ at high temperatures (1000°C). The crystallite size and lattice parameter increased with annealing temperature and the amount of ferrite incorporated in the SiO₂ matrix. The evolution of shape, size, and degree of agglomeration with the amount of ferrite incorporated in the SiO₂ matrix at 1000°C were investigated. The values of remanent and saturation magnetizations, anisotropy and coercivity, and the amount of ferrite incorporated in the SiO₂ matrix after annealing at 700°C and 1000°C were correlated with the particle morphology. The SiO₂ matrix exhibited diamagnetic behavior, while the Ni_0.5Cd_0.5Fe₂O₄ incorporated in the SiO₂ matrix showed a superparamagnetic behavior. The amount of ferrite and annealing temperature impacts the particle sizes, which further affects the magnetic characteristics. The incorporation of Ni_0.5Cd_0.5Fe₂O₄ nanoparticles into the inert SiO₂ matrix enabled the control of particle size, minimized particle agglomeration, and enhanced the magnetic properties.