Influence of Rare Earth (Nd sup(+3)) doping on structural and magnetic properties of nanocrystalline manganese-zinc ferrite

Abstract

Ultrafine nanopowders of Mn sub(0.6)Zn sub(0.4)Fe sub(2-x)Nd sub(x)O sub(4) (x = 0, 0.04, 0.06, 0.08, and 0.1) were prepared using combustion method. The influence of Nd sup(+3) doping on structural parameters, morphological characteristics and magnetic properties were investigated. Formation of pure spinel phase was confirmed using X-ray powder diffraction (XRPD). Nd sup(+3) doping in Mn-Zn ferrite samples have shown remarkable influence on all the properties that were under investigation. An increase in lattice constant commensurate with increasing Nd sup(+3) concentrations was observed in the samples. The crystallite size calculated from XRPD data and grain size observed from Transmission Electron Microscope showed a proportionate decrement with increment in rare earth doping. An increase in mass density, X-ray density, particle strain and decrease in porosity were the other effects noticed on the samples as a result of Nd sup(+3) doping. The corresponding tetrahedral, octahedral bond lengths and bond angles estimated from XRPD data have also shown substantial influence of the Nd sup(+3) doping. Magnetic parameters namely saturation magnetization (MS) and net magnetic moment ηB, estimated using vibrating sample magnetometer (VSM) were found to depend on the Nd sup(+3) doping. Mössbauer spectroscopy was employed to study the magnetic environment of Mossbauer active ions and detection of superparamagnetic behavior in nanocrystalline rare earth ferrite material. The isomer shift values obtained from Mössbauer spectra indicate the presence of Fe sup(+3) ions at tetrahedral site (A-site) and octahedral site (B-site), respectively.