Abstract
Dense CeO2 layers of 350 nm thickness, with columnar grains of size 25 nm, were RF-sputtered on silicon. 18O isotope exchange in the temperature range from 200 to 575 °C showed surface exchange at CeO2 as the rate-determining step, while diffusion through the polycrystalline thin layer was fast. The surface exchange coefficients controlled by surface or grain boundary processes were found to be ks = 2.7 × 10- 8 exp (frac(- 0.3 eV, k T)) cm s- 1 or kgb = 1 × 10- 9 exp (frac(- 0.3 eV, k T)) cm s- 1. Comparison with literature data on doped ceria revealed that surface exchange could be dominated by grain boundary processes. A lower limit for the diffusion coefficient was determined as 10- 15 cm2 s- 1 at 575 °C.
Original language | English |
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Pages (from-to) | 1205-1208 |
Number of pages | 4 |
Journal | Solid State Ionics |
Volume | 179 |
Issue number | 21-26 |
DOIs | |
Publication status | Published - 15 Sept 2008 |
All Science Journal Classification (ASJC) codes
- General Chemistry
- General Materials Science
- Condensed Matter Physics