Dopant distributions in rare-earth-doped alumina

Journal Article · Sat Feb 01 04:00:00 EST 1997 · Journal of the American Ceramic Society

DOI:https://doi.org/10.1111/j.1151-2916.1997.tb02840.x· OSTI ID:483661

Thompson, A M; Chan, H M; Harmer, M P; Williams, D B ^[1]; Soni, K K; Chabala, J M; Levi-Setti, R ^[2]

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1. Lehigh Univ., Bethlehem, PA (United States)
2. Univ. of Chicago, IL (United States)

The distribution of yttrium and lanthanum dopants has been mapped in yttrium- and lanthanum-doped polycrystalline aluminas using imaging secondary-ion mass spectrometry (imaging-SIMS). Both dopants segregate to grain boundaries and pore surfaces. On average, yttrium occupies 7.1%--9.0% of the available grain-boundary cation sites, whereas lanthanum occupies only 2.0%--5.2%. In 1,000-ppm-yttrium-doped alumina, an abundance of yttrium aluminum garnet precipitates also is observed. Implications of these observations to the creep behavior of alumina are discussed. The similarity in the segregation behavior of yttrium and lanthanum highlights the potential of lanthanum-doped alumina for improved creep properties.

• Sponsoring Organization: USDOE
• OSTI ID: 483661
• Journal Information: Journal of the American Ceramic Society, Journal Name: Journal of the American Ceramic Society Journal Issue: 2 Vol. 80; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
BULK DENSITY
CONCENTRATION RATIO
CREEP
DOPED MATERIALS
GRAIN BOUNDARIES
GRAIN SIZE
HOT PRESSING
ION SPECTROSCOPY
LANTHANUM
MICROSTRUCTURE
PRECIPITATION
YTTRIUM