Atomic-scale structure and chemistry of ceramic/metal interfaces -- 2: Solute segregation at MgO/Cu (Ag) and CdO/Ag (Au) interfaces
The first quantitative measurements of solute segregation at ceramic/metal (C/M) heterophase interfaces are presented for the MgO/Cu (Ag) and CdO/Ag (Au) systems. Interfaces are produced by internal oxidation of ternary alloys. Solute segregation at C/M interfaces is induced by intermediate-temperature annealing treatments. The Gibbsian interfacial excess of solute, {Gamma}{sub solute}, at these interfaces is determined in a direct, quantitative manner by atom-probe field-ion microscopy (APFIM). These measurements are complemented in the MgO/Cu (Ag) system by a composition analysis of this interface employing electron energy loss spectroscopy (EELS). Analyses of 15 {l{underscore}brace}222{r{underscore}brace} MgO/Cu (Ag) interfaces by APFIM show an average segregation level of (4.0 {+-} 1.9) x 10{sup 14} atoms/cm{sup 2} or 0.22 {+-} 0.10 effective monolayers at 500 C. Analyses of three {l{underscore}brace}222{r{underscore}brace} CdO/Ag (Au) interfaces show an average segregation level of (3.0 {+-} 1.0) x 10{sup 14} atoms/cm{sup 2} or 0.22 {+-} 0.07 effective monolayers at 400 C. Whereas {l{underscore}brace}222{r{underscore}brace} CdO/Ag (Au) interfaces in unannealed specimens show no evidence of gold segregation. These results are discussed in view of recent models of interfacial segregation.
- Research Organization:
- Northwestern Univ., Evanston, IL (US)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- FG02-96ER45597; FG02-87ER45322
- OSTI ID:
- 20005372
- 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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