Dilatometric study of a strontium ferrotitanate and calcium aluminate

Resumo

The effect of oxygen partial pressure on the dimensions of SrTi_0.7Fe_0.3O_{3 ± δ} strontium ferrotitanate (perovskite structure) and Ca₁₂Al₁₄O_{33 ± δ} calcium aluminate (mayenite structure) samples has been studied by dilatometry. The observed considerable variations in dimensions are characteristic of electronic–ionic mixed conductors with the perovskite structure. The effect observed in mayenite is substantially weaker, which can be understood in terms of specific features of its structural framework, made up of hollow, closed structural elements.