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

Auto-combustion process was used for synthetization of Ni1-xZnxFe2O4and 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 of zinc ions in the content, a decrease of the Curie temperature and coercive field value and an increase of the complex permeability real part value were observed, together with a shift of the ferrimagnetic resonance frequency value to lower ones. 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 complex permeability real part and higher values of the ferrimagnetic resonance frequency.