Yttrium-substituted Mg–Zn ferrites: correlation of physical properties with Yttrium content

Abstract

Yttrium- (Y) substituted Mg–Zn ferrites with the compositions of Mg0.5Zn0.5YxFe2−xO4 (0 ≤ x ≤ 0.05) have been synthesized by conventional standard ceramic technique. The effect of Y3+ substitution on the structural, electrical, dielectric and magnetic properties of Mg–Zn ferrites has been studied. The single phase of spinel structure with a very tiny secondary phase of YFeO3 for higher Y contents has been detected. The theoretically estimated lattice constant has been compared with measured experimental lattice constant. The bulk density, X-ray density and porosity have been calculated. The Energy Dispersive X-ray Spectroscopy (EDS) study confirms the presence of Mg, Zn, Y, Fe and O ions in the prepared samples. Frequency dependence of conductivity has been studied and an increase in resistivity (an order) has been observed. Frequency dependence of dielectric constant ( $$\varepsilon$$ ), dielectric loss tangent ( $$\tan \delta$$ ) has been studied and the lowering of $$\varepsilon$$ with the increase of Y content was noted. Dielectric relaxation time was found to vary between 15 to 31 ns. The saturation magnetization (Ms), coercive field (Hc), remanent magnetization (Mr) and Bohr magneton (µB) have been calculated. The variation of Ms has been successfully explained with the variation of A–B interaction strength due to Y substitution. The soft ferromagnetic nature also confirmed from the values of Hc. The complex permeability has been studied and the initial permeability was found to increase with Y up to x = 0.01, thereafter it decreases. The values of electrical resistivity and dielectric constant with proper magnetic properties suggest the suitability of Y-substituted Mg–Zn ferrites in microwave device applications.