Elastic stresses play a well-known and important role in the structure of thin films during growth. However, elastic effects can also greatly influence surface morphology of the substrate. One source of this influence, as has long been recognized is the elastic interactions between steps on surfaces. More recently, Marchenko has shown that surface stress can stabilize finite-size structures in surfaces, such as facets. Traditionally surface morphologies such as steps and facets have been measured by low-energy electron diffraction. However, the more recent development of ultra-high vacuum compatible microscopic techniques such as scanning tunneling microscopy, reflection electron microscopy, and low-energy electron microscopy, now make it possible to image steps and facets directly to obtain information about sizes and size distributions. This information in turn makes it possible to test the influence of stress on surface morphology directly.
Scanning tunneling microscopy and spectroscopy of finite-size twisted bilayer graphene