Fabrication of Nanostructure Ferrite Foam

Abstract

In this work, cobalt ferrite nanopowder was synthesized by Pechini type sol-gel method based on polyesterification reaction between citric acid, ethylene glycol and benzoic acid. Single phase cobalt ferrite nanopowders including 80 nm mean particle sizes were achieved after calcination treatment at 750ͦC for 1 hour. Obtained powder was subjected to fabrication a foam using pure urea as a spacer material. Pure urea with desired particle size was mixed by ferrite powder with 50-60 volume percentages and appropriate amounts of ethanol and wax. The mixture was molded in a steel die and compacted by one direction hydraulic press to achieve a disk with 1cm diameter and 1cm height. Green compacted disk was sintered under controlled heating rate condition from room temperature to 1000ͦC prohibition of foam structure collapse. XRD, SEM analysis results proved the formation of open cell foam having nanostructured pore wall. The samples proceeding survey demonstrated that the key factors through foam processing by this route are applied force at compact step and heating rate at sinter step. Moreover using the nanopowder let loading more amounts of spacer, also lead to decrease of inhomogeneity pore distribution, which are considerable characteristic in foam structures.