Ni/Zn ratio and La substitution effect on selected structural and magnetic properties of NiZn ferrites

Abstract Auto-combustion process was used for synthetization of Ni1-xZnxFe2O4 and Ni1-xZnxLa0.02Fe1.98O4 (x = 0, 0.3, 0.5, 0.64 and 0.7) ferrite samples to investigate their structural and selected magnetic properties. Standard characterization method such as X-ray diffraction, magnetic susceptibility temperature dependencies measurement, low-frequency hysteresis loops recording and complex permeability spectra were used on the research samples. The monophasic ferrite compounds have been prepared. For all samples, with an increase in the content of zinc ions, a decrease in the value of the Curie temperature and coercive field and an increase in the value of the real part of the complex permeability were observed, together with a shift in the value of the ferrimagnetic resonance frequency to lower values. Substituted samples showed some differences, such as slightly higher values of the Curie temperature and coercive field, and at the same time slightly lower values of the real part of the complex permeability and higher values of the ferrimagnetic resonance frequency.