Abstract
Using the Metropolis algorithm Monte Carlo technique solute-atom segregation is studied at two vicinal grain boundaries (GBs) - the ∑ = 5/(0 0 2)/0 = 36.89° symmetrical twist and the ∑ = 5/(3 1 0)/θ = 53.13° symmetrical tilt - at 850 K. on the Ni-rich side of the Ni-Pt phase diagram, over the concentration range 0-10 at. % Pt. Unlike the Pt-rich side of the phase diagram the structures of both GBs remain stable in this concentration range. The dilute limit behavior for most GB sites extends to at least 0.1 at.%. At higher concentrations the effective segregation energies steadily decrease with increasing solute concentrations, due to solute-solute interactions between segregated atoms, until saturation occurs. It is argued that simple statistical mechanical models, e.g., the Fowler-Guggenheim model do not work well, even in the case of simple vicinal GBs.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 259-265 |
| Number of pages | 7 |
| Journal | Interface Science |
| Volume | 6 |
| Issue number | 4 |
| DOIs | |
| State | Published - Dec 1998 |
Funding
This research is supported by the National Science Foundation (grant No. DMR-9419171, Dr. B.A. McDonald, grant officer). This work is also partially supported by grant number DMR920002N, and it utilizes the CRAY Y-MP and CRAY 2 systems at the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign.
Keywords
- Fowler-Guggenheim segregation models
- Grain boundaries
- Langmuir-McLean
- Metropolis Monte Carlo
- Nickel-platinum alloys
- Simulation
- Solute-atom segregation
- Twist and tilt boundaries
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- General Materials Science
- Condensed Matter Physics