Individually injected current pulses with conducting-tip, tapping-mode atomic force microscopy

Individually injected current pulses during the operation of a conducting-t ip tapping-mode atomic force microscope have been measured under a range of experimental conditions. The bias pulses, applied during the tip-sample co ntact time, did not perturb the tapping operations, and eliminated artifact s associated with displacement currents. The reproducible injection of curr ent density pulses on the order of 10 muA/nm(2) per tap can be applied to s preading resistance measurements and to storage applications employing, for example, phase change by Joule heating and magnetic switching by spin-pola rized current. (C) 2001 American Institute of Physics.