ON THE LIMITS OF THE SPECTROSCOPIC ABILITY OF AFM AND THE INTERACTIONBETWEEN AN AFM TIP AND A SAMPLE

The spectroscopic ability of the atomic force microscopy (AFM) is cons idered and limits are found on the parameters of a small object which may be detected by means of AFM. For example, in the attractive mode i t is shown that AFM is able to distinguish between small objects consi sting of different materials provided their volumes are greater than ( 5 X 5 X 5) atoms. Moreover, the interaction between an AFM tip and a p lane sample is examined in the framework of the continuous approach. T he choice of a paraboloid AFM tip is substantiated.