MIGRATION OF METALS ON GRAPHITE IN SCANNING-TUNNELING-MICROSCOPY

Metals such as Au deposited on graphite substrates are found to migrat e very easily when biased in scanning tunneling microscopes. Depending upon the him thickness and the tip voltage, a hillock surrounded by g rooves or a hole surrounded by hillocks with a height of similar to +/ -10 nm and a lateral dimension of similar to 100 nm are formed. The me chanism of these surface-modification phenomena is discussed in light of electro- and thermomigration.