THE ROLE OF SURFACE STRESS IN RECONSTRUCTION, EPITAXIAL-GROWTH AND STABILIZATION OF MESOSCOPIC STRUCTURES

The role of stress at solid surfaces in a vacuum environment and in co ntact with a liquid electrolyte in reconstruction, epitaxial growth an d self-organization or stabilization of mesoscopic structures is criti cally reviewed. Starting from the definitions of the surface stress, t he status of our current understanding of the physical origin of the s urface stress on clean surfaces and of the changes of the stress upon deposition of adsorbates or foreign material is discussed. Changes in the surface stress can be measured using the cantilever bending method . The relevant equations for the elastic bending are derived. It is sh own that the data analysis in previous work needs revision. Several ex amples are presented where the surface stress is either the driving fo rce for the reconstruction of the surface or is at least facilitating the reconstruction. The traditional concept of the critical thickness of a heteroepitaxially grown pseudomorphic film is based on the consid eration of the elastic strain energy caused by the misfit of the film and substrate lattices. It is shown that the interface stress contribu tes significantly to the elastic energy and hence to the stability or instability of pseudomorphic thin films. Inhomogeneous surface stresse s can give rise to a self-organization of mesoscopic structures on sur faces. The theoretical background for this phenomenon is reviewed and examples are discussed.