Temperature Programmed Reduction of Ferriter

The reduction property of ferrite MFe₂O₄ （M=Fe, Mn, Co, Ni） with spinel structure was studied by temperature programmed reduction reduction technology in temperature range of 298~1073K combining with XRD and Mossbauer spectra. Effects of ferrite composition and the second metal component M （Mn, Co, Ni） on ferrite reduction property were also discussed.In the TPR profiles, the sample ofγ-Fe₂O₃ appeared two peaks at 673 and 863 K assigned to Fe₃O₄ and α-Fe respectively. The ferrites MFe₂O₄ （M=Mn, Co, Ni） with the spinel-type structure all appeared two TPR peaks which were ascribed to MO-FeO andα-Fe, andα-Fe,resprctively. The peak temperature of reducing to MO-FeO decreased in order of Fe, Co, Mn,Ni, While the order of the peak temperature of further reducing toα-Fe is on the opposite.The introduction of the second metal component stabilized ferrous phase, the interaction between MO and FeO, the stability of MO-FeO solid solution and the ability of ferrite MFe₂O₄ reducing into MO-FeO increased in the order of Fe, Co, Mn, Ni, while the ability of MO-FeO reduced intoα-Fe decreased in this order.