Extreme temperature gradient promoting oxygen diffusion in yttria‐stabilized zirconia: A molecular dynamics study

Abstract

AbstractThe 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 () in YSZ, but the diffusion behavior in small‐sized YSZ samples under non‐isothermal condition where the temperature gradient () could be significant remaining elusive. Herein, we disclose the previously unrevealed effect of extreme on the self‐diffusion behavior of in both pristine and strained YSZ. It is found that the self‐diffusion coefficient () experiences a nearly one‐fold increase under an extreme around 60 K/Å. The diffusion direction tends to be toward regions of high temperature. Uniaxial stress is revealed to reduce due to the increased activation energy of ions, whereas promotes the self‐diffusion in the stressed system. These results underscore the role of in influencing the self‐diffusion behavior of YSZ, providing a theoretical guideline for examining ceramics serving in extreme environments.