  The paper describes the peculiarities of acquirement and interpretation of
images of current distribution through the sample surface when operating in
I-AFM mode. It shows that I-AFM and SCM modes can be successfully used only for
small scanning fields (no more than 5x5 square micrometer), since during the
scanning process the continuous change in the area of the probe tip and,
therefore, in the contact area between the probe and the sample surface is
observed because of the abrasion of the tip. At the same time electrical modes
of AFM could not be recommended for the investigation of nano objects, because
there appear a number of difficulties in results interpretation, caused by the
big curvature radius of the probe tip and, therefore, by the big surface area
of electrical contact. The paper also demonstrates the peculiarities of
acquirement and interpretation of CVCs for individual points on the sample
surface in I/V Spectroscopy mode. It is shown that it is practically impossible
to use I/V Spectroscopy mode for additional investigation of the surface by
acquiring of CVCs in the points of interest (where heterogeneities in
topography or current through the surface are observed) on the sample surface
in I-AFM mode, because of the big temperature drift and hysteresis of
piezoceramics. Recommendations for improving the possibilities of the method
are given in the paper.
