Structural and magnetic properties of nanocrystalline Mg-Cd ferrites prepared by oxalate co-precipitation method

Polycrystalline spinel ferrites with general formula Mg1-x Cd (x) Fe2O4 (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) were prepared by oxalate co-precipitation method using high purity sulfates. The samples were sintered at 1,050 A degrees C for 5 h. The structural properties of these samples were investigated by XRD, SEM and FTIR techniques. The X-ray diffraction analysis confirms the formation of single phase cubic spinel structure of all the samples. The lattice constant, X-ray density, physical density, porosity, crystallite size, site radii (r (A), r (B)), bond length (A-O, B-O) on tetrahedral (A-site) and octahedral (B-site) were calculated for the samples. The lattice constant increases with increase in Cd2+ content. The X-ray density increases with increase in Cd2+ content. The crystallite size calculated by Scherrer formula is in the range of 27.79-30.40 nm. Physical densities are calculated by Archimedes principle. The SEM study shows that the grain size increases with increasing Cd2+ content. The FTIR spectra shows two strong absorption bands around 576 and 431 cm(-1) on the tetrahedral and octahedral sites, respectively. The dependence of saturation magnetization on Cd2+ content suggests that A-B and B-B super exchange interaction are comparable in strength. Neel's two sub lattice model is applicable up to x a parts per thousand currency sign 0.4, while Y-K three sub lattice models (canted spin) is predominant for x a parts per thousand yen 0.4.