Spreading of smectic-Adroplets: Structure and dynamics of terraces

The spreading of smectic-A droplets on a smooth, high-energy surface has been studied using x-ray reflectivity, ellipsometry, and video imaging at the Brewster angle. These droplets have a layered structure and terraces are evidenced. The dynamics of expansion or retraction of these terraces are investigated and compared with recent theoretical predictions. In a last stage, holes open in the single remaining terrace and their growth ultimately leads to a complete breaking up of the terrace. The nematic and isotropic phases dewet the first terrace, and holes also appear in the layer by raising the temperature above the smectic domain.