Gold-coated conducting-atomic force microscopy probes.

Some aspects of the performance of gold-coated conductive probes used in conducting atomic force microscopy (C-AFM) technique are discussed. The resistance of the nanocontact between the gold-coated AFM tip and the graphite substrate has been monitored at various applied forces. For small forces (<50 nN), resistance on the order of a few kiloohms was observed. Minimal contact resistance was observed for forces in the range 100-150 nN, beyond which the tip seems to undergo plastic deformation. The resistance of the nanocontact increased when current on the order of 100 microA was allowed to pass through, finally resulting in melting of the gold coating.