Abstract
The segregation at a (100) surface of Au is studied slightly above the order-disorder transition at . Based on a semi-infinite lattice-gas model with nearest- and next-nearest-neighbor interactions, we find within mean-field theory that close to the surface and in the disordered phase the Au concentration decays exponentially towards its bulk value. The corresponding decay length Λ increases as (T- upon approaching , where < denotes the spinodal temperature of the order-disorder transition. Without using any adjustable parameters, we obtain theoretical predictions in good quantitative agreement with recent x-ray-scattering data from this surface.
- Received 14 December 1994
DOI:https://doi.org/10.1103/PhysRevB.52.2107
©1995 American Physical Society