D. Johnson—contributing editor
Grain-Boundary Diffusion of Cr in Pure and Y-Doped Alumina
Article first published online: 10 MAY 2007
Journal of the American Ceramic Society
Volume 90, Issue 5, pages 1551–1555, May 2007
How to Cite
Bedu-Amissah, K., Rickman, J. M., Chan, H. M. and Harmer, M. P. (2007), Grain-Boundary Diffusion of Cr in Pure and Y-Doped Alumina. Journal of the American Ceramic Society, 90: 1551–1555. doi: 10.1111/j.1551-2916.2007.01584.x
This work was financially supported by the Office of Naval Research under contract number N00014-05-1-0232, and the Pennsylvania Department of Community and Economic Development under contract number C000007361.
- Issue published online: 10 MAY 2007
- Article first published online: 10 MAY 2007
- Manuscript No. 22506. Received November 20, 2006; approved December 29, 2006.
The diffusive transport of chromium in both pure and Y-doped fine-grained alumina has been investigated over the temperature range 1250°–1650°C. From a quantitative assessment of the chromium diffusion profile in alumina, as obtained from electron microprobe analysis, it was found that yttrium doping retards cation diffusion in the grain-boundary regime by over an order of magnitude. The Arrhenius equations for the undoped and Y-doped samples were determined to be: δDb=(4.77±0.24) × 10−7 exp (−264.78±47.68 (kJ/mol)/RT)(cm3/s) and δDb=(6.87±0.18) × 10−8 exp (−284.91±42.57 (kJ/mol)/RT)(cm3/s), respectively. Finally, to elucidate the mechanism for this retardation, the impact of yttrium doping on diffusion activation energies and prefactors was examined.