A model based upon defect chemistry was developed to describe the creep behavior of La0.2Sr0.8Fe0.8Cr0.2O3−δ. The model was based on partial clustering of divalent B site cations and O vacancies. According to the model, the increased strain rates at low PO2 were due to increased mobility of B site cations in linked clusters. The cluster concentration was proportional to the O partial pressure, PO2m with m = −1/2 in accordance with the creep data. The model described the creep behavior in the entire PO2 range used in the measurements. Models based on random non-interacting defects or including ambipolar diffusion, Sr segregation or partial decomposition cannot give the observed pO2 dependence of the creep behavior.

Stress-Induced Diffusion and Defect Chemistry of La0.2Sr0.8Fe0.8Cr0.2O3-δ - Defect-Chemistry Based Modeling. G.Majkic, A.J.Jacobson, K.Salama: Solid State Ionics, 2004, 167[3-4], 255-62