Electrical transport properties of CoMn0.2−xGaxFe1.8O4 ferrites using complex impedance spectroscopy

Abstract

In this study, we report the influence of Ga content on the microstructural, magnetic, and AC impedance properties of Co-based ferrites with compositions of CoMn0.2−xGaxFe1.8O4 (x=0, 0.1, and 0.2) prepared by the solid-state reaction method. Experimental results showed that the as-prepared Co-based ferrites had a single-phase spinel structure; the Curie temperature of Co-based ferrites decreased with increasing Ga content. All ferrite samples exhibited a typical hysteresis behavior with good values of saturation magnetization at room temperature. The electrical properties of Co-based ferrites were investigated using complex impedance spectroscopy analysis in the frequency range of 100 kHz-50 MHz at temperatures of 150 to 250 oC. The impedance analysis revealed that the magnitudes of the real part (Z’) and the imaginary part (Z”) of complex impedance decreased with increasing temperature. Only one semicircle was observed in each complex impedance plane plot, which revealed that the contribution to conductivity was from the grain boundaries. It was found that the relaxation time for the grain boundary (τgb) also decreased with increasing temperature. The values of resistance for the grain boundary (Rgb) significantly increased with increasing Ga content, which indicated that the incorporation of Ga into Co-based ferrites enhanced the electrical resistivity.

Exploration through Structural, Electrical, and Magnetic Properties of Al3+ Doped Ni–Zn–Co Nanospinel Ferrites

“…33 Only one semicircle is displayed in the present study that confirms only one relaxation mechanism inside the systems. 33,40 Moreover, significantly apparent one semicircle for all of the compositions indicates that the grain boundary effects lead the conduction mechanism while the contribution from the grains is too weak to distinguish. 33 2.7.…”