Surface structure of donor graphite intercalation compounds by scanning tunneling microscopy

Abstract
Scanning tunneling microscopy (STM) has been used to study the surface of C6Li as a stage-1 donor graphite intercalation compound from a submicrometer down to the atomic scale. Ordered superlattices commensurate as well as incommensurate with the graphite lattice have been observed. The measured STM corrugation at small bias voltage (<200 mV) has been found to be similar to graphite whereas at larger bias voltage a strong decrease of the corrugation was observed. This experimental result is compared with recent theoretical predictions.