Preparation and Characterization of Ni Ferrite Powders by Urea Decomposition

Abstract

The effects of process parameters such as concentration ratio of urea and nickel(II) iron(II, III) salt solutions, period of aging and the pH of the solution on the synthesis of Ni ferrite from aqueous solutions by decomposition of urea was investigated to develop ferrite-containing porous ceramic fiber materials. The XRD patterns of the precipitation showed that at pH value lower than six both akagenite (β-FeOOH) and Ni ferrites were formed simultaneously. At pH above six, Ni ferrite single phase could be obtained. The precipitates heat treated at 300 °C under nitrogen atmosphere result in a fine powder with BET areas ranging from 8.9 to 22.8 m2 g—1. The morphology of Ni ferrite shows agglomerates of spherical particles ranging in the size 50–200 nm.