Beilstein J. Nanotechnol.2012,3, 207–212, doi:10.3762/bjnano.3.23
process can be understood as a hysteresis of forces between approach and retraction of the tip. In this paper, we present the direct measurement of the whole hysteresis loop in force-spectroscopy curves at 77 K on the PTCDA/Ag/Si(111) √3 × √3 surface by means of a tuning-fork-based NC-AFM with an
about 0.22 eV/cycle.
Keywords: atomic force microscopy; energy dissipation; force spectroscopy; hysteresis loop; PTCDA/Ag/Si(111) √3 × √3; Introduction
Noncontact atomic force microscopy (NC-AFM) is a powerful tool for the study of surface properties. The invention of the frequency-modulation mode (FM
in three different phases, namely the herringbone, square and hexagonal phases.
Results and Discussion
Figure 1a shows an STM 250 nm × 250 nm overview scan of the PTCDA/Ag/Si(111) √3 × √3 surface after the deposition of ~0.3 ML PTCDA. The PTCDA molecules grow from step edges or between steps and form