Journal of Materials Science

, Volume 25, Issue 1, pp 223–232 | Cite as

Iron species in fusion-cast, glassy-phase-containing corundum materials; EPR and susceptibility analyses

  • Reinhard Stösser
  • Rudof Brenneis
  • Ines Ebert
Article

Abstract

By means of EPR, susceptibility, EMP, light-microscopic, thermal and chemical methods the influence of production conditions and subsequent treatments on glassy-phase-containing corundum materials were studied. Melting of the system (Al2O3, SiO2, Na2O, Fe3O4) under reductive conditions leads to a reduction of Fe3+ species contained to Fe2+ and even to Fe0 clusters with ferromagnetic behaviour. Both species markedly influence the mechanical properties of the material by increase of their volumes in consequence of oxidation in subsequent thermal processes. The following model with regard to the localization of the iron species in the system ensues: Fe(III) in corundum, Fe2O3, Fe3O4 and (scarcely) in the glassy phase; Fe(II) in the glassy phase, FeAl2O4 (hercynite) as a solid solution in corundum, and Fe3O4; (Fe0) clusters in corundum. It is therefore not surprising that grinding of the compact material considerably alters the magnetic properties of the samples.

Keywords

SiO2 Al2O3 Fe3O4 Magnetic Property Corundum 

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Copyright information

© Chapman and Hall Ltd 1990

Authors and Affiliations

  • Reinhard Stösser
    • 1
  • Rudof Brenneis
    • 2
  • Ines Ebert
    • 3
  1. 1.Department of ChemistryUniversity of HumboldtBerlinGDR
  2. 2.Central Institute of Inorganic Chemistry of the Academy of Sciences of the GDRGDR
  3. 3.Central Institute of Physical Chemistry of the Academy of Sciences of the GDRGDR

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