1. Instrumentation and operating modes

1.1 Microscope

A typical force microscope schematic is shown in figure 1 . A miniature tip, attached to the end of a cantilever, is brought close to the surface of a sample placed on a displacement stage (XYZ scan). The relative displacement of the tip with respect to the sample provides either a map of the measured quantity, or an "isograndeur" surface, if a servo loop adjusts the sample height to keep the measured quantity constant.

The deflection or torsion of the spring under the effect of the interaction...