Structural and Physical Properties of Synthesized (Nickel- Zinc– Gallium) Ferrites Doped with Rare-Earth Elements”

Abstract

Structural, micro-structural, magnetic properties and cations distribution were studied for NiFe2O4 and (Ga/Zn/Gd) substituted NiFe2O4 spinel ferrite samples. The samples prepared in both dry (solid state) and/or wet chemical (citrate, sol-gel). The crystallite sizes depend on the preparation procedures and the annealing temperatures at which they were prepared. The lattice parameter, oxygen position parameter and crystallite size are found to be increased by the increasing in the annealing temperature, whereas the strains are decreased. For the samples prepared by chemical method with particle size in nano scale; Mössbauer spectra at room temperature shows superparamagnetic double. cation distributions Significantly have an effect on the magnetic properties of the materials under investigation. Obtained results confirm that at room temperature NiFe2O4 parent compound is a fully inverted spinel (δ=0 ± 0.01) with a cubic symmetry of the lattice. The analysis of Zn/Ga doped NiFe2O4 shows that the cubic symmetry is conserved. It is observed that as gadolinium introduced into the system, the deviation from single phase and existence of additional peaks indexed as gadolinium silicate oxide phase, which is present in all the ceramic samples due to interaction of gadolinium with crucible. Substitution of Gd3+ and increasing of Zn2+ content increase the lattice parameter and crystallite size, which can be explained on the basis of ionic radii. The broad diffraction peaks indicate that for the samples prepared in chemical method, crystallized in the nano scale.