THEORY OF SCANNING-TUNNELING-MICROSCOPY IMAGES OF INTERCALATED GRAPHITE SURFACES

The electronic and structural properties of intercalated graphite surfaces imaged with scanning tunneling microscopy (STM) have been studied theoretically, with use of a modification of the tight-binding model of Blinowski et al. The corrugation amplitude (CA) and carbon-atom site asymmetry (CSA) are sensitive to the number, m, of graphite layers covering the first guest layer, to the amount of transferred charge and its distribution to the surface subband structure. The CA and CSA can be used to map the stage domains across a freshly cleaved surface. The CSA has a surprising dependence on the charge transfer and on m. We explain the unusual absence of atomic scale features in the STM images of BiCs-graphite reported by Gauthier et al. The STM images of the surfaces of both donor and acceptor graphite intercalation compounds are discussed. © 1990 The American Physical Society.