Tuning the dielectric and structural properties of erbium substitution on cobalt ferrites

Abstract

Spinel ferrites having the composition CoErxFe2-xO4(x = 0.0, 0.01, 0.02, 0.03, 0.04, 0.05) was synthesized through micro emulsion method. To study the structural, IR spectra, morphology and composition and electrical properties of these spinel ferrites, the characterization of samples was done by XRD, FTIR, SEM and Dielectric properties respectively. Spinel ferrites XRD patterns revealed that the structure was crystallite and single phase. By doping the rare earth metal Erbium, it was shown that there were variations in lattice parameters. The range of Crystallite size was in 19- 25nm which was calculated by Scherer formula. FTIR recorded the IR spectra, the absorption bands of IR spectra revealed that all samples were spinel ferrites. SEM also confirmed the shape of the particle and grain size that is found to be in agreement with the XRD data, it also showed monotony in the morphology. Real and imaginary parts of impedance Z՛ and Z″ in the frequency range of 1MHz to 3 GHz was plotted. The results show that the impedance decreases with increasing frequency. In order to determine the grain effect, the real and imaginary parts electrical modulus was plotted with increasing Erbium substitution. The effect of frequency in high frequency region gives the variation in electrical modulus. Furthermore, real and imaginary parts of dielectric constant were plotted as a function of frequency. The results show the significant effect in the high frequency region. Also the same behavior was observed in case of tangent loss. Ac conductivity was determined showing the increasing trend with increasing frequency. Excellent dielectric properties suggest that Er3+ has significant effects for the application of high frequency devices.