Dewetting on the surface of rutile

Abstract

After annealing a continuous SiO₂ film on the (001) surface of TiO₂, the film dewets and then spreads to form a complex pattern. The final droplet morphology displays a densely branching morphology similar to those seen in computer-simulated models. It is proposed that Bénard-Marangoni convection cells form within the film before dewetting occurs. The formation of Bénard-Marangoni convection cells prior to dewetting results in the uniform size and spacing of the droplets on the surface. These convection cells form at temperature when the TiO₂ substrate dissolves into the SiO₂ thin film. The change in composition results in regions of differing surface tensions and therefore leads to the formation of the convection cells.