Nickel/Zinc ratio and lanthanum substitution effect on structural and magnetic properties of nickel zinc ferrites

Improvement of NiZn ferrites properties by means on Ni/Zn content ratio modification and by partial substitution of Fe³⁺ ions by La³⁺ ions is presented. Ni_{x}Zn_{1-x}Fe₂O₄ and Ni_{x}Zn_{1-x}La_{0.02}Fe_{1.98}O₄ samples of small particles were prepared by self-propagated combustion method. X-ray spectroscopy was used for structural analysis, temperature dependence of magnetic susceptibility was used for evaluation of chemical and phase composition. Analysis showed that pure spinel structure without secondary phase caused by La ions for all values of Ni/Zn content was present. Noticeable growth of the magnetic susceptibility at room temperature was observed with rising of Zn²⁺ ions content