Investigation of grain-boundary segregation in ceramic oxides by analytical scanning transmission electron microscopy. [MgO-NiO; Al/sub 2/O/sub 3/-Y/sub 2/O/sub 3/; NiO-Cr/sub 2/O/sub 3/; NiO-Al/sub 2/O/sub 3/]
Analytical scanning transmission electron microscopy (AEM) was used to study grain-boundary solute segregation in the systems MgO-NiO, Al/sub 2/O/sub 3/, NiO-Cr/sub 2/O/sub 3/, and NiO-Al/sub 2/O/sub 3/. Electron beam spreading within the specimen was incorporated into a model to quantitatively measure solute segregation. Grain-boundary segregation occurred in Al/sub 2/O/sub 3/-Y/sub 2/O/sub 3/ and NiO-Cr/sub 2/O/sub 3/ but was not detected in MgO-NiO and NiO-Al/sub 2/O/sub 3/ specimens. These results and the quantitative measurements agree with equilibrium solute segregation theories. Microhardness measurements indicate no difference in hardness between the grain boundary and the matrix for Cr-doped NiO, a system in which segregation was detected.
- Research Organization:
- Lehigh Univ., Bethlehem, PA
- OSTI ID:
- 6799036
- Journal Information:
- J. Am. Ceram. Soc.; (United States), Journal Name: J. Am. Ceram. Soc.; (United States) Vol. 63:9/10; ISSN JACTA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
CHROMIUM COMPOUNDS
CHROMIUM OXIDES
CRYSTAL STRUCTURE
ELECTRON MICROSCOPY
GRAIN BOUNDARIES
MAGNESIUM COMPOUNDS
MAGNESIUM OXIDES
MICROSCOPY
MICROSTRUCTURE
NICKEL COMPOUNDS
NICKEL OXIDES
OXIDES
OXYGEN COMPOUNDS
SEGREGATION
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES