Effect of Zn doping on temperature and frequency dependence of dielectric permittivity and dielectric relaxation for synthesized tetragonal copper-gallium ferrite

CuFe2O4 and Cu1−xZnxGa0.3Fe1.7O4 with (0.0 ≤ x ≤ 0.5) are synthesized. Crystallographic phase transformation from tetragonal-to-cubic is occurred at x = 0.1. Dielectric permittivities (ɛ′ and ɛ′′) and dielectric loss tangent (tan δ) are studied for the prepared samples from room temperature up to 700 K in the frequency range (102-105 Hz). The relation of tan δ with frequency at different temperatures shows relaxation spectra where the relaxation time and the maximum frequency of the hopping process are determined. Dielectric anomaly at the transition temperature Tc is pronounced in the relation of dielectric permittivity with temperature. The determined Tc is found to decrease linearly with increasing Zn concentration. The variation of (ɛ′, ɛ′′ and tan δ) with frequency and temperature displayed a strong dependence on both of gallium and zinc concentrations. Obtained results are explained based on the cation-anion-cation and cation-cation interactions over the octahedral site in the spinel structure.