“…1,3 The short-range interaction force can be determined by force spectroscopy (FS), in which forces are measured as a function of distance. In particular, FS measurements have been performed on a variety of surfaces, including semiconductors, 4,5 metals, 6,7 metal-oxides, 8 ionic crystals, 9,10 single-walled carbon nanotubes (SWNT), 11 and graphite (0001). 12 Recently, the capability of atomic-scale imaging and spectroscopic probing of interaction forces was extended to organic molecules by using a CO-functionalized metallic tip, 13 and the observed contrast was assigned to Pauli repulsion.…”