Abstract
We report the direct observation of internal layering in thin ( ) liquid films of nearly spherical, nonpolar molecules, tetrakis(2-ethylhexoxy)silane, using synchrotron x-ray reflectivity. The Patterson functions have secondary maxima indicating layer formation, and model-independent fitting to the reflectivity data shows that there are three electron density oscillations near the solid-liquid interface, with a period of (consistent with the molecular dimensions). The oscillation amplitude has a strong inverse dependence on the substrate surface roughness.
- Received 20 November 1998
DOI:https://doi.org/10.1103/PhysRevLett.82.2326
©1999 American Physical Society