Preparation of ferrites from the combustion of metal nitrate-oxalyl dihydrazide solutions

Abstract

Spinel ferrites, MFe₂O₄ (M= Co, Ni, Cu, Zn) have been prepared by a redox chemical reaction between aqueous solutions of metal nitrates, ferric nitrate and oxalyl dihydrazide (ODH). On rapid heating the reaction mixture undergoes an abrupt exothermic redox chemical reaction that facilitates atomic scale mixing of the cations. This leads to the formation of stoichiometrically pure and single-phase nanoparticle ferrites at comparatively reduced temperature (400^oC) and in less time than possible by the conventional ceramic method. The final thermolysis products (ferrites) have been characterized by various physico-chemical techniques, i.e., XRD, IR, SEM and magnetic studies (saturation magnetization and Curie temperature).