| Oxynitride glass appears at the grain boundary of dense silicon nitride based ceramics sintered with metal oxides. Iron diffusion in oxynitride glass, similar in composition to that formed at the grain boundary of such ceramics, is studied. In order to know the mechanism of iron diffusion and valancy and coordination state of iron, findings of Mossbauer and EPR spectroscopies are corroborated in terms of possible occupancy of iron in such glasses. Tetravalency of iron or ferric [Fe3+]tet is indicated, though a straightway conclusion cannot be forwarded in favour of any of them right now. |
