1. Extreme temperature gradient promoting oxygen diffusion in yttria‐stabilized zirconia: A molecular dynamics study.
- Author
-
Guo, Jian, Yin, Yan, and Yi, Min
- Abstract
The oxidation resistance of yttria‐stabilized zirconia (YSZ) thermal barrier coatings and conductivity of YSZ solid oxide fuel cells are closely related to the diffusion of oxygen ions (O2−$\text{O}^{2-}$) in YSZ, but the O2−$\text{O}^{2-}$ diffusion behavior in small‐sized YSZ samples under non‐isothermal condition where the temperature gradient (∇T$\nabla T$) could be significant remaining elusive. Herein, we disclose the previously unrevealed effect of extreme ∇T$\nabla T$ on the self‐diffusion behavior of O2−$\text{O}^{2-}$ in both pristine and strained YSZ. It is found that the O2−$\text{O}^{2-}$ self‐diffusion coefficient (D$D$) experiences a nearly one‐fold increase under an extreme ∇T$\nabla T$ around 60 K/Å. The diffusion direction tends to be toward regions of high temperature. Uniaxial stress is revealed to reduce D$D$ due to the increased activation energy of ions, whereas ∇T$\nabla T$ promotes the O2−${\text{O}}^{2-}$ self‐diffusion in the stressed system. These results underscore the role of ∇T$\nabla T$ in influencing the self‐diffusion behavior of YSZ, providing a theoretical guideline for examining ceramics serving in extreme environments. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF