Temperature dependence of surface layering in a dielectric liquid

The temperature dependence of the density oscillations (layers) at the free surface of tetrakis(2-ethylhexoxy)silane, a nonmetallic molecular liquid, was investigated using x-ray reflectivity. Below ~2150.3em0exK, the layer parameters weakly vary with temperature, if at all. Above this temperature, the layer spacings and intrinsic layer widths increase continuously, until there is no identifiable layering above 2300.3em0exK. This transition occurs at T∕Tc≈0.23, a temperature region that is usually accessible in metallic liquids but is preempted by freezing in many dielectric liquids.