Direct observation of elastic and plastic deformations at Au(111) surfaces

Three forms of elastic and plastic deformations at Au(111) surfaces have been observed by high-resolution electron microscopy. These are normal expansion of the first surface interplanar spacing, lateral expansions through surface dislocations, and the development of hill-and-valley structure or elastic buckling depending upon the sample morphology. These effects are interpreted as evidence for a positive, tangential surface pressure (surface stress) consistent with effects in gold alloys, and small-gold-particle internal and electronic structures.