Report
Initial sintering stage kinetics of CeO2 studied by stepwise isothermal dilatometry
The kinetics of the initia l sinterin g stage of CeO2 is studied by a new dilatometric technique in which the heating of the sample is controlled by its shrinkage rate. By this technique the shrinkage characteristically takes place in "isothermal steps" which allows both the mechanism and its activation energy to be determined in a single experiment.
The basic equations necessary to evaluate the shrinkage data are described, and using these equations on the curves recorded for CeO2 it is shown that the controlling mechanism for the initia l sintering stage for this oxides is grain-boundary diffusion of Ce4+-ions with an activation energy of 119.4 kcal/mole (5.2 eV).
The corresponding diffusion coefficient is estimated to vary between 8.5 x 10-17 - 3.1 x 10-15 cm2/sec (1005 - 1099°C).
| Language: | English |
|---|---|
| Publisher: | Risø National Laboratory |
| Year: | 1985 |
| Series: | Denmark. Forskningscenter Risoe. Risoe-r |
| ISBN: | 8755010857 and 9788755010857 |
| ISSN: | 01062840 |
| Types: | Report |
