Smectic liquid crystal monolayers on graphite observed by scanning tunneling microscopy

By means of scanning tunneling microscopy, it is observed that molecules of the form n-alkylcyanobiphenyl, where n = 8 to 12, form two-dimensional crystalline domains when adsorbed onto graphite. The layer spacings measured by tunneling microscopy are 20% larger than those measured previously on bulk material by x-ray diffraction. The structure of the adsorbed molecules is quite different from that of the bulk.