Oxygen diffusion in Sr_3YCo_4O_(10.5): An electrical conductivity relaxation and thermogravimetric analysis approach

摘要

Electrical conductivity relaxation Chemical oxygen diffusion coefficients and chemical surface exchange rates along with oxygen selfdiffusion coefficients in dense samples of Sr_3YCo_4O_(10.5) + δ were studied by using a combination of electrical conductivity relaxation (ECR) measurements and thermogravimetric analysis (TGA) data in the temperature range of 650 °C-900 °C. Arrhenius behavior, A = A_0 exp (E_A/RT), was observed with activation energies of E_A~(chem)= 1:16 ± 0:01 eV, E_A~(DO)= 1:56 ± 0:01 eV and E_A~(kchem) = 0:76 ± 0:05 eV for the chemical oxygen diffusion coefficient, the oxygen self-diffusion coefficient, and the chemical surface exchange rate, respectively. The thermodynamic factor changes with temperature from 611 at 650 °C to 177 at 900 °C.