Observation of surface layering in a nonmetallic liquid.
Oscillatory density profiles (layers) have previously been observed at the free surfaces of liquid metals but not in other isotropic liquids. We have used x-ray reflectivity to study a molecular liquid, tetrakis(2-ethylhexoxy)silane. When cooled to T/Tc approximately 0.25 (well above the freezing point for this liquid), density oscillations appear at the surface. Lateral order within the layers is liquidlike. Our results confirm theoretical predictions that a surface-layered state will appear even in dielectric liquids at sufficiently low temperatures, if not preempted by freezing.
Mo
Haiding
H
Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA.
Evmenenko
Guennadi
G
Kewalramani
Sumit
S
Kim
Kyungil
K
Ehrlich
Steven N
SN
Dutta
Pulak
P