Study of the Structural, Electrical and Magnetic Properties of Rare Earth Yttrium Doped Mn-Zn Ferrites

Abstract

Mn-Zn ferrites belong to a group of spinels studied extensively because of their interesting technical properties. The present work focused on rare earth (Y) substituted for Fe in Mn-Zn ferrites are well-known technological magnetic materials used for manufacturing of multilayer chip inductor and applications in various electrical devices. The series of ferrite sample of composition Mn0.5Zn0.5YxFe2-xO4 where x = 0.00, 0.02, 0.04, 0.06, 0.08 and 0.10 were prepared by solid state reaction technique sintered at 1200C with 2 hours holding time. The X-ray diffraction analysis revealed that rare earth free sample shows formulation of single phase cubic spinel structure with no extra peak but Y substituted for Fe in Mn-Zn samples show additional peaks manifested the formation of secondary phase presumably YFeO3. Lattice constant primarily increase up to x = 0.04 and thereafter decreases. X-ray density of this composition is slightly greater than that of their bulk densities due to existence of some pores in the bulk sample. The average grain size decrease monotonically with increasing Y content while the porosity of studied samples follow the opposite trend. The average grain size has significant influenced on the magnetic properties such as permeability. A significant change in initial permeability has been found to increase or decrease by the amount of Y3+ in Mn0.5Zn0.5YxFe2-xO4 ferrite. But the initial permeability decreases with increasing Y ions in ferrite except x = 0.06. Relative Quality factor (RQF) signifies the merit of the material from the application point of view and found to have high values for the samples with x= 0.04 and x= 0.08.The saturation magnetization (MS), coercivity (Hc) and remanent induction (Mr) have been calculated from M – H curve at room temperature. The decrease of MS with increasing of Y substitutions has been explained as the effect of dilution of Fe3+ magnetic moment by nonmagnetic Y3+. The electrical DC resistivity decreases with increasing temperature for all studied samples manifesting semiconducting nature of Y substituted Mn-Zn ferrites. The dielectric constant is found to decrease continuously with increasing frequency and remain almost constant at higher frequency range. Dielectric polarization and conduction process arise due to the local displacements of electrons which in turn gives the dielectric constants.