Characterization of metastable tetragonal forms in ZrO{sub 2}-2.8 mol% Y{sub 2}O{sub 3} ceramics
- Universidad Nacional de La Plata (Argentina). Dept. de Fisica
- Comision Nacional de Energia Atomica, Buenos Aires (Argentina). Dept. de Materiales
This paper deals with a perturbed angular correlation investigation of the microstructure and subsequent thermal evolution of a commercial ZrO{sub 2}-2.8 mol% Y{sub 2}O{sub 3} ceramic powder and of a pellet obtained upon sintering the powder at 1,450 C. The perturbed angular correlation results, complemented by those of X-ray diffraction and Raman spectrometry, indicate that the metastable tetragonal phase exhibits two hyperfine interaction forms instead of the interaction associated with the conventional t-ZrO{sub 2} phase, both having different oxygen vacancy configurations around zirconium sites. While the powder sample exhibits mainly a very defective tetragonal form, the pellet exhibits a slightly distorted one as the major form. As temperature is increased, a reversible transformation between both forms occurs involving a redistribution of the oxygen vacancy. Once the transition is completed, the oxygen vacancy movement is described by a fast relaxation regime with an activation energy E{sub act} = 0.50 {+-} 0.04 eV.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 247902
- Journal Information:
- Journal of the American Ceramic Society, Journal Name: Journal of the American Ceramic Society Journal Issue: 4 Vol. 79; ISSN 0002-7820; ISSN JACTAW
- Country of Publication:
- United States
- Language:
- English
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