A Study of Structural and Magnetic Properties of Mg-Cu Mixed Spinel Ferrites

Abstract

Mg-Cu ferrites are well-known technological magnetic materials finding applications in various electrical devices. The present work is focused on the influence of substitutions and sintering temperature on structural and magnetic properties of Mg-Cu ferrites. Mg1- xCuxFe2O4 where x=0.0, 0.1, 0.2, 0.3, 0.4 and 0.5 samples have been prepared by conventional ceramic method, sintered at 1100°C, 1200°C and 1200°C (quenched). Some physical properties such as lattice parameters, density, porosity, magnetic properties such specific magnetization and hyperfine magnetic field. The structural phase identification was carried out by X-ray diffraction (XRD), microstructure analysis of the samples following scanning electron microscope (SEM), specific magnetization measurement by vibrating sample magnetometer (VSM) and Mössbauer spectroscopy analysis. The X-ray diffraction analysis revealed that all the samples are crystallize in single phase cubic spinel structure. It was found that lattice parameter and porosity decreases with the Cucontent. It was observed from the microstructure study that the grain size increase with the increasing Cu-content. Thoughout the investigation it has also been found that grain size increases with increasing sintering temperature. Magnetization measurements have been accomplished by VSM. It was found that saturation magnetization increases with Cu-content with high value of 36.77 emu/gm for x = 0.5 at sintered temperature 1200°C (quenched), as well as microstructure grain size increases and grain growth clear visible. Interesting experimental results on magnetization at different sintering temperature have been found. Other structural and magnetic properties such as chemical isomer shift, quadruple splitting and hyperfine field were determined by Mössbauer spectroscopy. The velocity scale of a thin 57Fe sample and the isomer shifts are given relative to the centroid of the spectrum. The shifts of Fe atoms in all Mg-Cu ferrites sample behave trivalent ions. The spectrum for the Mg1-xCuxFe2O4 ferrites consists of six lines which are broad as compared with Mössbauer spectrum of a pure 57Fe samples. One of the magnetic signals is a sextet typical of those associated with a good ferromagnetic at room temperature. In a ferromagnetic order all Fe with antiparallel behavior is consistent with a diluted exchange coupling between magnetic Fe-ions on the tetrahedral site to octahedral site.