STM measurements on graphite using correlation averaging of the data

Abstract

SUMMARY Images of the (0001) surface of highly oriented pyrolytic graphite observed using scanning tunnelling microscopy, in both constant distance and current imaging modes, show a strong asymmetry of the unit cell. This asymmetry depends on the tunnelling current and voltage. We have also found clear evidence that multiple‐tip tunnelling occurs. To improve the resolution of the imaged unit cells, a method of correlation averaging is introduced.