Infrared absorption spectroscopic study of Nd 3+ substituted Zn-Mg ferrites

Compositions of polycrystalline Zn x Mg 1− x Fe 2− y Nd y O 4 ( x = 0.00, 0.20, 0.40, 0.60, 0.80 and 1.00; y = 0.00, 0.05 and 0.10) ferrites were prepared by standard ceramic method and characterized by X-ray diffraction, scanning electron microscopy and infrared absorption spectroscopy. Far infrared absorption spectra show two significant absorption bands, first at about 600 cm −1 and second at about 425 cm −−1 , which were respectively attributed to tetrahedral (A) and octahedral (B) sites of the spinel. The positions of bands are found to be composition dependent. The force constants, K T and K O , were calculated and plotted against zinc concentration. Compositional dependence of force constants is explained on the basis of cation-oxygen bond distances of respective sites and cation distribution.