Soft chemical synthesis and characterization of Ni_0.65Zn _0.35Fe₂O₄ nanoparticles

Mixed ferrite nanoparticles of Ni0.65 Zn0.35 Fe2 O4 using metal nitrates were prepared by three different low temperature methods of sol gel in polyvinyl alcohol matrix, coprecipitation with NaOH as coprecipitating base, and sol gel in citric acid matrix, separately to estimate the influence of synthesis on the structural and magnetic parameters of this high saturation magnetization NiZn ferrite composition. In the final stage of the synthesis, the coprecipitated sample was washed and filtered several times before drying and finally heat treated at 350 °C for 1 h to get the ultrafine powder. Whereas the other two samples, which were transformed into dried gel after mixing and drying, were heat treated at 350 °C for 1 h, respectively, to find out the dried gel burnt out in a self-propagating combustion manner to form a fluffy powder. X-ray diffraction, transmission electron microscopy, and vibrating sample magnetometer measurements are performed on all three samples. Though the composition is the same for all three samples, the results of these characterizations are found to be different for different synthesis methods and also much different from their corresponding bulk counterpart. However, the magnetic performance of these nanoparticles is primarily determined by their respective particle size in all three samples. The results are analyzed in terms of the microstructure and magnetic performance.