Electrical conductivity and chemical diffusivity of NiAl2O4 spinel under internal reforming fuel cell conditions

摘要: NiAl2O4 spinel was formed by solid state reaction. Its electrical conductivity measured in the temperature range of 680–940 °C and under various oxygen-rich environments, as well reducing conditions. From dependence conductivity, activation energies for conduction increase decreasing oxygen partial pressures. pressure dependence, defect structure material analysed. The change with respect to PO2 can be attributed singly doubly ionized nickel vacancies. chemical diffusivity oxide determined relaxation upon abrupt surrounding atmosphere. diffusion coefficient is order magnitude 10−4 cm2 s−1.