Atomic-scale structure and chemistry of ceramic/metal interfaces -- 1: Atomic structure of {l{underscore}brace}222{r{underscore}brace} MgO/Cu (Ag) interfaces
Ceramic/metal (C/M) {l{underscore}brace}222{r{underscore}brace} MgO/Cu (Ag) heterophase interfaces, prepared by internal oxidation, are studied by scanning transmission electron microscopy (STEM). The observed spacing between misfit dislocations (1.45 nm) in a {l{underscore}angle}110{r{underscore}angle} projection is in agreement with the prediction of Bollmann's geometric O-lattice theory and experimental values in the literature for {l{underscore}brace}222{r{underscore}brace} MgO/Cu interfaces. It is concluded that the {l{underscore}brace}222{r{underscore}brace} MgO/Cu (Ag) interfaces are semicoherent and contain a trigonal network of pure edge misfit dislocations parallel to {l{underscore}angle}110{r{underscore}angle}-type directions, with an (a/6)(211)-type Burgers vector. Misfit dislocations are also found in a standoff position at a distance of a single (111) spacing of the Cu (Ag) matrix. Extra intensity at the interface, in some angular dark-field images indicates silver segregation, in agreement with out atom-probe field-ion microscope results. On the metal side of the interface, extra intensity is observed in five atomic layers, which corresponds to a total silver enrichment of approximately 0.7 effective monolayers.
- Research Organization:
- Northwestern Univ., Evanston, IL (US)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- FG02-96ER45597; AC05-84OR21400
- OSTI ID:
- 20005371
- Journal Information:
- Acta Materialia, Vol. 47, Issue 15-16; Conference: Materials Science and Mechanics of Interfaces, La Jolla, CA (US), 10/25/1998--10/30/1998; Other Information: PBD: 12 Nov 1999; ISSN 1359-6454
- Country of Publication:
- United States
- Language:
- English
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