Effect of holmium substitution on structural, electrical, and magnetic properties of manganese-Zinc ferrites

Abstract

Influence of Ho3+ substitution on the structural, magnetic and dielectric properties of various Mn0.55Zn0.45HoxFe2-xO4 are thoroughly investigated. X-ray diffraction patterns indicated that the samples possess fairly single-phase cubic spinel structure for a small amount of Ho3+ substitution. The value of lattice parameter increases with increasing Ho3+content. The bulk density decreases and porosity increases with increasing Ho3+content. FESEM images showed that Ho3+ have a significant effect on the grain growth. The maximum value of real part of initial permeability (338) is obtained for x=0.03 sample. Due to the addition of Ho3+ there is a decrease of saturation magnetization from 71 to 44 emu/g and increase of the coercivity from 21 to 70 Oe. It was observed that real part of the dielectric constant decrease with increasing of frequency on the basis of Wagner and Koop's theory. The mechanism of conduction may be explained by the small polaron hopping model.