Abstract
X-ray reflectivity measurements of the binary liquid Ga-Bi alloy reveal a dramatically different surface structure above and below the monotectic temperature . A Gibbs-adsorbed Bi monolayer resides at the surface in both regimes. However, a thick, Bi-rich wetting film intrudes between the Bi monolayer and the Ga-rich bulk for . The wetting film's internal structure, not hitherto measured, is determined with resolution, showing a concentration gradient not predicted by theory and a highly diffuse interface with the bulk phase.
- Received 12 July 1999
DOI:https://doi.org/10.1103/PhysRevLett.84.4385
©2000 American Physical Society