The study of structural, frequency and temperature dependence of electrical and dielectric properties of CuO-substituted Ni-Zn nanocrystalline ferrites for MLCI applications

The Cu2+ ion-substituted Ni-Zn ferrites were synthesised by the citrate gel auto-combustion method. The structural and micro-structural analyses of all samples were done using XRD and SEM, respectively. XRD studies confirmed that all samples belong to a cubic spinel structure. The cation distributions of all samples were estimated using relative X-ray intensity calculations. Room temperature, temperature variation, electrical resistivity, initial permeability and dielectric properties were carried out by an impedance analyser. The dielectric and permeability values decreased with increasing frequency. The addition of Cu2+ ions in the present system modifies the cation distribution which results in a gradual decrease of magnetisation values. The temperature dependence of initial permeability showed a sharp decrease with increasing temperature. This indicates the formation of a single phase of materials. The maximum permeability value obtained at x = 0.10 is directly related to the grain size. These temperature variation studies indicate that all these materials are well-suitable for MLCI applications.