Morphological Transformation of Palladium Caused by Measurement of a Scanning Tunneling Microscope

Abstract
It was observed that scanning the surface of palladium (Pd) for imaging with a scanning tunneling microscope (STM) caused the morphological change of the surface: The morphology of Pd was transformed from a rough surface to a flat one. This observation suggests that the surface was changed so as to reduce the surface energy. In the case of platinum, the morphology also changed to a certain degree. However, the change was not as drastic as compared with that of Pd. It is supposed that this morphological transformation was due to an electrostatic force (image force) between the STM tip and the metal surface.