The grain-boundary conductivity (σgb) of 8-mol%-ytterbia-stabilized zirconia increased markedly with heat treatment between 1000° and 1300°C with a slow heating rate (0.1°C/ min) before sintering. The extent of the σgb improvement was the same or larger than that via Al2O3 addition. The heat treatment did not affect the grain-interior conduction when sintered at 1600°C, while Al2O3-derived scavenging significantly did, given the larger increment of total conductivity in the heat-treated sample. The formation of a silicon-containing phase in a discrete form was suggested as a possible route of scavenging the resistive phase from the correlation between average grain size and σgb.
|Number of pages||3|
|Journal||Journal of the American Ceramic Society|
|Publication status||Published - 2001 Nov 1|
ASJC Scopus subject areas
- Ceramics and Composites