Growth and electronic properties of NaCl on HOPG

We report the growth of cross-shaped islands of NaCl on highly oriented pyrolytic graphite (HOPG) and discuss the mechanism of formation and growth kinetics within the framework of diffusion limited aggregation (DLA). These structures are investigated using scanning probe microscopy. The shape and structure of these islands can be finely controlled by the deposition conditions. The islands exhibit large atomically flat surfaces which are ideal supports for investigations of the fundamental properties of deposited atoms, molecules or clusters. Bismuth nanostructures were deposited on the NaCl islands and were investigated via scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS). The tunneling spectra recorded for particles on NaCl are surprisingly similar to those measured for similar particles on HOPG. We suggest that this is due to a ‘dead’ layer commonly observed for Bi thin films.