Synthesis and Characterization of Mixed Ferrites

In this work we prepare nanocrystalline mixed ferrites by equilibrated low entropy routes with generic formula of MnxNi1-xFe2O4. Two series of samples have been prepared where “x” varies as 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5 the samples have been prepared by chemical co-precipitation route. For the first calculated amount of salts of Mn, Fe and Ni were dissolved in deionized water and stirred for a few minutes. 0.1 M NH4OH solution was then slowly added drop-wise under vigorous stirring. The alkali addition was continued till the pH of the solution was 10 and was left undisturbed for 1hour for complete digestion. The precipitate was then washed thoroughly till pH 7 and then heated to 600 0 C. For the next series “x” was kept fixed at 0.5 and the same synthesis steps were repeated. The sample was divided into three batches and heat treatment was performed at 600 0 C, 900 0 C. The samples were checked for their phase purity by x ray diffraction which confirmed the spinel phase without any impurity. Dielectric measurements were performed within a frequency window of 1 Hz to 1 MHz the dielectric dispersion can be well explained by Koops and Maxwell – Wagner theory. Raman spectroscopy also gave detailed information about the structural order of the samples.