High-temperature compressive creep behaviour of perovskite-type oxides SrTi1-xFexO3-δ

Compressive creep tests have been performed on mixed ionic-electronic conducting perovskite-type oxides SrTi1-xFexO3-δ (STF, x = 0.3, 0.5 and 0.7). Observed activation energies and stress exponents, at 800-1000 °C and in the stress range 10 100 MPa, indicate that the steady-state creep rate of STF under these conditions is predominantly limited by cation lattice diffusion (Nabarro-Herring creep). The effective stress exponents reflect a contribution of dislocation creep to the mechanism of creep in STF30 (x = 0.3). The observed creep rates are compared with those exhibited by related perovskite-type oxides, and are discussed in view of the possible application of STF as oxygen transport membrane (OTM).