Influence of Rare Earth (Y) Ion Substitution on the Structural, Electrical and Magnetic Properties of Cobalt-Zinc Ferrites

Abstract

A series of rare earth Y3+ ion substituted Co-Zn ferrites Co0.5Zn0.5YxFe2-xO4 (x=0.00 to 0.08 in step of 0.02), have been synthesized by conventional double sintering technique from the oxide powders of Co, Zn, Fe and Y. The XRD, FESEM, EDS, DC resistivity, dielectric measurements, VSM, Curie temperature (Tc) analysis have been used to investigate structural, morphological, electrical and magnetic properties. Single phase of cubic spinel structure has been confirmed up to x<0.06, and a small amount of secondary phase YFeO3 has also been detected for x>0.06. The lattice parameter initially decreases than increase with yttrium concentrations. The FESEM image shows the grains and grains boundaries are distinct and uniformly distributed and the purity has also been endorsed from the EDS spectra. The average grain size decreases at x= 0.02 and then increases with Y substitution. The long range mobility of charge carriers and presence of localized charge carriers with retreat from the Debye-like behavior in the compositions have been explored using electric modulus and impedance. The magnetic strength diminishes owing to existence of magnetic dilution in the A-B interactions subsequent the Tc declines with the x contents. The value of saturation magnetization decreases with increasing Y3+ contents that indicates the domain wall motion become tougher due to substitution of foreign ions Y3+ that possess larger ionic radius. Therefore, the Y3+ substituted Co0.5Zn0.5YxFe2-xO4 (x=0.00 to 0.08 in step of 0.02) ferrites with high resistivity and low losses has implications to be used in high frequency and power supply devices applications.