Solid State Ionics, Vol.301, 156-162, 2017
Evaluation of isotope diffusion coefficient and surface exchange coefficient of ScSZ series oxide by oxygen isotope exchange method
In this work, the Isotope diffusion coefficient (D*) and surface exchange coefficient (k*) of Sc2O3 stabilized ZrO2 (ScSZ) series oxide, 6 mol%Sc2O3-ZrO2 (6ScSZ), 10 mol% Sc2O3-ZrO2 (10ScSZ) and 10 mol%Sc2O3-1 mol% CeO2-ZrO2 (10Sc1CeSZ) were evaluated by using oxygen isotope exchange method. It was found that these ScSZ oxides showed a relatively higher D* value; 10Sc1CeSZ showed 1.1 x 10(-7) cm(2) s(-1), 10ScSZ showed 93 x 10(-8) cm(2) s(-1) and 6ScSZ showed 6.1 x 10(-8) cm(2) s(-1) at 711 degrees C, respectively. In addition, its activation energy was 1.0 eV for 10Sc1 CeSZ, 1.1 eV for 10ScSZ and 1.0 eV for 6ScSZ, respectively. The rapid change of D* due to the phase transition was also confirmed at around 600 C in the case of 10ScSZ. The surface exchange coefficient (le) of these ScSZ oxides showed a relatively high value at lower temperature. 10Sc1CeSZ showed 1.3 x 10(-8) cm s(-1) at 498 degrees C under lower vapor pressure of less than 20 Pa. (C) 2017 Elsevier B.V. All sights reserved.
Keywords:ScSZ;SIMS;Isotope diffusion coefficient;Surface exchange coefficient;Oxygen isotope exchange