Oxygen tracer diffusion in La1 − xSrxCoO3

✍ Scribed by J.L. Routbort; R. Doshi; M. Krumpelt

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 551 KB
• Volume: 90
• Category: Article
• ISSN: 0167-2738
• DOI: 10.1016/s0167-2738(96)00402-x

✦ Synopsis

Tracer diffusion of "0 in dense, polycrystalline La, _,Sr,CoO, for x = 0.1 has been measured in the temperature range 400 to 600°C and at 500°C for x = 0.2 at an oxygen partial pressure of 1 X lo5 Pa. Depth profiles were obtained by secondary ion mass spectrometry. The diffusion coefficient for La,,,Sr,,,CoO, is given by D = (17-247) exp[(-23228 kJlmole)lRT] cm'/s. This value is several orders of magnitude lower than D extrapolated from the results for x = 0.2 measured in the 700~900°C temperature range. One possible explanation for the discrepancy is that the two measurements reflect different diffusion paths. As expected, La,,,Sr,,CoO, exhibits a higher diffusivity at 500°C than does La,.&,.,CoO,.