Influence of Ga substitution on the magnetic and electric behavior of Cu0.5Zn0.5Fe2O4 compound

Ga3+ with closed 3d-shell is used to substitute Fe3+ in the Cu0.5Zn0.5Fe2-xGaxO4 with (0.0=<x=<0.3). XRD study on the synthesized samples confirms the presence of single-phase spinel structure. Well-ordered Mossbauer spectra at 12K are obtained for the studied compounds using installed and well-calibrated closed-cycle variable temperature cryostat. The determined cation distribution from the spectral analysis at 12K indicated that Ga substitutes for Fe at the octahedral B-site in this system. Hyperfine parameters are found to be dependent on Ga content. The relation of conductivity with temperature revealed semiconducting behavior with change in the slope at the transition temperature. Variation of the universal exponent s with temperature indicates the presence of correlated barrier hopping (CBH) mechanism in these materials. Relaxation spectra are observed in the relation of dielectric loss tangent with frequency where, relaxation time and maximum frequency of the relaxation process are determined. Dielectric anomaly at Tc is pronounced in the relations of dielectric permittivities (ε' and ε'') with temperature. The results are explained based on the cation-anion-cation and cation-cation interactions over B-site in the spinel structure