Structural and Magnetic Рroperties of Copper Substituted Mg-Ferrites

Abstract

Polycrystalline ferrite powders of Mg1-xCuxFe2O4 (x = 0.2, 0.4, 0.6, 0.8, 1) system synthesized by ceramic technology have been investigated. Samples showed the non-monotonic dependency of heat generation effect in AC magnetic field with increasing concentration of copper. To reveal peculiarities of the structural and magnetic state of the samples and their influence on the heat generation ability we performed a complex study, including X-ray diffractometry, Mössbauer spectroscopy, Scanning electron microscopy, measurements of temperature dependencies of susceptibility and saturation magnetization, hysteresis parameters and FORC. Typical ferrimagnetic character with small coercivity and saturation magnetization was found. We carried out that anomalous influence of Cu2+ ion substitution respectively to the Mg1-xCuxFe2O4 ferrite powder manifested in heat generation ability rise up to x=0.6. The subsequent sharp reducing of this characteristic were accompanied by the main phase crystal structure distortion followed by phase separation to cubic and tetragonal structure. This was matched by in an increase of ferrite particles crystallite size and size distribution appearance. The saturation magnetization and Curie temperature dependencies observed for powders via Cu substitution was explained by phase composition, the cations distributions between ferrite sublattices, modulation of exchange interaction.