Abstract
The order-disorder phase transition at the surface at -type alloys has been studied using the Bragg-Williams theory. A simple electronic theory for the order-disorder transition at the surface is also presented. In agreement with experiments for Au one finds that the order parameter and in particular the discontinuity in the order parameter at the transition temperature is strongly reduced for the first three atomic surface layers. We study also the effect of surface segregation on the order-disorder transition at the surface. One finds that due to segregation the order parameter can disappear at the surface at temperatures below . Also, atomic ordering may suppress segregation.
- Received 3 January 1977
DOI:https://doi.org/10.1103/PhysRevB.15.4769
©1977 American Physical Society