Spectroscopic studies of the effect of addition of Y3+ on structural characteristics of Ni-Zn ferrites

Three groups of Ni-Zn ferrite samples of the general formula; Ni1-xZnxYyFe2-iyO4, were prepared by a double-sintering ceramic method, in an attempt to examine the solubility of yttrium ions on Ni-Zn ferrite. The theoretical values of the tetrahedral and the octahedral bond lengths, the oxygen parameters and the lattice parameters were calculated. X-ray diffraction was used to analyze the relationship between structural characterization and Zn2+ ion concentration, indicating good agreement with theoretical calculations. It was observed that the lattice parameters of cubic spinel of the investigated samples are not functions of Y3+ ion concentration, i.e. the process of dissolution of any ratio of yttrium in the lattice never occurs. It is proved that the nonstoichiometric system can redistribute itself to produce a single phase of cubic spinel under a suitable sintering process. The IR spectra obtained at room temperature in the range 1000-300 cm(-1) for all compositions show splitting of the two bands upsilon(2) and upsilon(3) and an excessive number of bands besides three fundamental absorption bands upsilon(1) (601-549 cm(-1)), upsilon(2) (512-406 cm(-1)), and upsilon(3) (380-305 cm(-1)). Most of the bands were assigned on the basis of the analysis of structural characterization properties. The splitting of the two bands upsilon(2) and upsilon(3) was discussed as being due to the nature of the octahedral site in the ferrite in general.