Cu2+-modified physical properties of Cobalt-Nickel ferrite

•In this work, Influence of Cu and cation redistribution is discussed in detail.•Theoretical and experimental results related to distribution, lattice constant are found to be consistent.•Substitution of Cu significantly modifies the magnetization, permeability, grain size and resistivity. The present study focused on structural, magnetic and electrical properties of Cu substituted Co-Ni ferrite nanoparticles synthesized by sol-gel combustion method. X-ray diffraction, Fourier Transform infra-red spectroscopy (FTIR), magnetization, magnetic permeability and resistivity measurements were carried out to study the structural, magnetic and electrical properties. X-ray diffraction pattern confirms single phase spinel formation. Crystallite size determined from Scherer’s method increases with Cu concentration. Distribution of cations was estimated from X-ray line intensity calculations, suggest that the majority of Cu2+ ions occupy octahedral (B) site. Saturation magnetization exhibit increasing trend from 40emu/g (x=0.0) to 60emu/g (x=0.4) with Cu concentration, though higher magnetic moment Ni ions are replaced by lower magnetic moment Cu ions. Magnetic permeability increases with increasing Cu concentration and shows a flat profile in the frequency range 1–50MHz. Significant modification in DC electrical resistivity and activation energy are explained on the basis of hopping mechanism.