Research of the magnetic properties of feerites in the NiO-CoO-ZnO system

Abstract

Oxide systems containing transition metal cations possess important technological properties. So, for example, ferrites of cobalt, nickel, manganese, zinc are used in magnetic, electrical materials as catalysts for a number of reactions. Technological schemes for producing such compounds require the use of high-temperature heat treatment and sophisticated equipment. The use of hydrophase chemical synthesis methods is the basis for producing ferrites of transition materials with a given set of properties. A characteristic recent trend is the development of technologies for producing nanodispersed ferrites. The dependence of the magnetic characteristics of ferrites in the CoO-NiO-ZnO system by the simplex method was studied. Ferrites Ni-Zn, Co-Zn, Co-Ni were synthesized in the form of nanoparticles using the method of processing contact nonequilibrium low-temperature plasma. The crystalline microstructure of the samples was elucidated using X-ray diffraction and X-ray diffraction methods. It has been established that for spinel ferrites, in particular, the choice of a divalent cation directly determines their magnetic behavior. The effect of the mutual influence of the content of various cations on the saturation magnetization and the coercive force by the simplex method is determined. Magnetic studies using a vibrating magnetometer showed that under these synthesis conditions, low magnetization values are observed for Ni-Zn ferrites and high for the entire series of Co-Zn, Co-Ni ferrites. An increase in the content of cobalt cations leads to an increase in coercive force in all compositions. A positive effect of nickel cations on the value of saturation magnetization of ferrites on the side of the Ni-Zn triangle and the opposite on the side of Ni-Co, EPR spectra showed that the value of the resonance field and line width corresponds to the value of magnetic saturation.