Dielectric behaviour of Zn substituted Cu nano-ferrites

Abstract

Herein, the dielectric properties such as permittivity (real part ε′ and imaginary part ε′′) and dielectric loss tangent (tanδ) are reported for Zn substituted Cu ferrites (Cu1−xZnxFe2O4; 0≤x≤1) composite using the sol–gel auto-combustion method. The variations of real and imaginary part of dielectric constant, tanδ and AC conductivity (σac) are studied at room temperature in the frequency range of 100Hz–120MHz. The real part of dielectric constant decrease with increasing frequency and the imaginary part (ε′′) varies with frequency showing the characteristic peak for each sample. The relation of tanδ with frequency shows relaxation spectra. Further, the σac tended to increase with increase in frequency. The variation in dielectric constant may be explained on the basis of space charge polarization, according to Maxwell and Wagner two-layer model. The dielectric constant and tanδ as a function of temperature are also studied with different temperatures ranging from 323K to 583K.