In:
Journal of the American Ceramic Society, Wiley, Vol. 79, No. 7 ( 1996-07), p. 1793-1800
Abstract:
The effects of the dopants, Mg 2+ , Ca 2+ , Sr 2+ , Sc 3+ , Yb 3+ , Y 3+ , Gd 3+ , La 3+ , Ti 4+ , Zr 4+ , and Nb 5+ , on the grain boundary mobility of dense CeO 2 have been investigated from 1270° to 1420°C. Parabolic grain growth has been observed in all instances. Together with atmospheric effects, the results support the mechanism of cation interstitial transport being the rate‐limiting step. A strong solute drag effect has been demonstrated for diffusion‐enhancing dopants such as Mg2+ and Ca 2+ , which, at high concentrations, can nevertheless suppress grain boundary mobility. Severely undersized dopants (Mg, Sc, Ti, and Nb) have a tendency to markedly enhance grain boundary mobility, probably due to the large distortion of the surrounding lattice that apparently facilitates defect migration. Overall, the most effective grain growth inhibitor at 1.0 % doping is Y 3+ , while the most potent grain growth promoter is either Mg 2+ (e.g., 0.1%) or Sc 3+ at high concentration (greater than 1.0%).
Type of Medium:
Online Resource
ISSN:
0002-7820
,
1551-2916
DOI:
10.1111/jace.1996.79.issue-7
DOI:
10.1111/j.1151-2916.1996.tb07997.x
Language:
English
Publisher:
Wiley
Publication Date:
1996
detail.hit.zdb_id:
2008170-4
detail.hit.zdb_id:
219232-9
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