Surface stress-driven instabilities of a free film

Abstract

The effect of surface stress on the stability of free unconstrained solid films was investigated. The general thermodynamic criteria for film stability was first determined to show that two different morphological instabilities are possible, depending on the sign of the surface stress. The first morphological instability was found to correspond to a self-induced euler buckling mode and the second to an accordionlike wrinkling of the film surfaces. The results show that the surface stresses can have a profound effect on the morphological stability of thin films.