The tracer diffusion of 18O in dense polycrystalline samples of La1-xSrxCoO3, when x was equal to 0.1, was measured at temperatures ranging from 400 to 600C. Samples with x equal to 0.2 were studied at 500C, under an O partial pressure of 0.1MPa. Depth profiles were measured by means of secondary ion mass spectrometry. It was found that the activation energy for O diffusion in La0.9Sr0.1CoO3 was 232kJ/mol. The diffusivities were several orders of magnitude lower than the values which were extrapolated from published data at 700 to 900C (for samples with x = 0.2). This discrepancy was tentatively attributed to a difference in diffusion path. It was confirmed that La0.8Sr0.2CoO3 had a higher diffusivity at 500C than that of La0.9Sr0.1CoO3.

J.L.Routbort, R.Doshi, M.Krumpelt: Solid State Ionics, 1996, 90[1-4], 21-7