Effect of chromium substitutions on some properties of NiZn ferrites

Compositions having the general formula Ni0.6Zn0.4CrtFe2-tO4 with t=0.00, 0.05, 0.10, 0.15, 0.20 and 0.25 were prepared by the usual ceramic processing from high purity oxides. The samples were sintered at 1250 °C in static air atmosphere. X-ray diffraction and IR absorption spectra were used for analysing the composition. Lattice parameter, true density, bulk density, porosity and shrinkage were measured for the samples. A scanning electron microscope investigation was also carried out. It is observed that all samples have a single phase with spinel cubic structure. Lattice parameter, true density, bulk density are found to increase with increasing Cr concentration, whereas both porosity, shrinkage and grain size showed a decreasing trend with the Cr content.