CAPILLARY INSTABILITIES IN THIN, POLYCRYSTALLINE FILMS.

Abstract

The primary focus of instability discussed in this paper is beading, which is the process by which an initially uniform film which has been deposited on a substrate, breaks up into an array of beads or islands. The author examine the thermodynamics of the beading process and the effects of small perturbations on an initially uniform, flat film. They find that small perturbations do not lead to beading and that perturbations with amplitudes sufficient to bring the film surface into contact with the substrate are required. The physical origin of these types of pertubations are elucidated, and it is shown that these perturbations may be associated with microstructural defects. The dynamical aspects of beading are also discussed.