Structural and Electrical Studies of Nanocrystalline Fe2O3 Prepared by Microwave Assisted Solution Combustion Method with Mixed Fuel Approach

Abstract

This research work comprises synthesis of haematite (Fe2O3) nanoparticles using microwave assisted sol gel auto combustion method using solution combustion reaction between ferric nitrate as oxidizer and a mixture of urea and glycine fuel as reducer. In this fuel mixture, urea was taken as stoichiometric fuel and glycine was added as excess fuel to alter the exothermic properties of redox reaction between ferric nitrate and urea. The synthesized powder were characterized by XRD, FT-IR, TGA-DTA showing that the powders were composed of polycrystalline oxides with crystallite size of 30 nm with gamma Fe2O3 phase without sintering. The phase transition from gamma Fe2O3 to alpha haematite occurs at temperature of 482˚C. The curie temperature was calculated from Gouy’s balance and found to be 250 K. The electrical conductivity of nano Fe2O3 in pellet form was studied by impedance analyser at different temperature and frequencies. The variation of dielectric constant, ac conductivity with temperature and frequencies was also studied.