DETERMINATION OF THE SPRING CONSTANTS OF PROBES FOR FORCE MICROSCOPY SPECTROSCOPY/

A direct, accurate and convenient procedure for calibrating the spring constants of probes used for force microscopy/spectroscopy is describ ed. It amounts to deflecting an 'unknown' cantilever with a 'standard' lever, where the standard lever has been precalibrated. The absolute and relative accuracies of the procedure are +/-20-30% and +/-10-20%, respectively; the former is limited by uncertainties in the determinat ion of the spring constant for the 'standard' lever, as well as that f or the 'unknown'. The method differs from others of the static deflect ion variety by its exploitation of the routine features of current ins truments. The technique is compared with other static and dynamic meth ods currently being used.