POINT-DEFECTS AND TRANSPORT IN BINARY AND TERNARY, NONSTOICHIOMETRIC OXIDES

Discussed are: (i) experimental results for the variation of the oxyge n content, the electrical conductivity and the iron tracer diffusion i n fayalite, Fe2SiO4, (ii) the relationship between point defects, the deviation from stoichiometry, delta, in Fe3-deltaO4 and the iron trace r diffusion, (iii) the deviation from stoichiometry and the cation tra cer diffusion in iron-based spinels of the type (MexFe1-x)(3-delta)O-4 and (iv) the influence of near-boundary regions in polycrystalline Fe 3-deltaO4 and Cu2-deltaO on the overall variation of the oxygen conten t as a function of the oxygen partial pressure.