title: Temperature dependence of the energy dissipation in dynamic force microscopy.
abstract: The dissipation of energy in dynamic force microscopy is usually described in terms of an adhesion hysteresis mechanism. This mechanism should become less efficient with increasing temperature. To verify this prediction we have measured topography and dissipation data with dynamic force microscopy in the temperature range from 100 K up to 300 K. We used 3,4,9,10-perylenetetracarboxylic-dianhydride (PTCDA) grown on KBr(001), both materials exhibiting a strong dissipation signal at large frequency shifts. At room temperature, the energy dissipated into the sample (or tip) is 1.9 eV/cycle for PTCDA and 2.7 eV/cycle for KBr, respectively, and is in good agreement with an adhesion hysteresis mechanism. The energy dissipation over the PTCDA surface decreases with increasing temperature, yielding a negative temperature coefficient. For the KBr substrate, we find the opposite behaviour: an increase of dissipated energy with increasing temperature. While the negative temperature coefficient in the case of PTCDA agrees rather well with the adhesion hysteresis model, the positive slope found for KBr points to a hitherto unknown dissipation mechanism.
authors.affiliation: Fachbereich Physik, Universität Duisburg-Essen, D-47048 Duisburg, Germany.
authors.forename: Tino
authors.initials: T
authors.lastname: Roll
authors.forename: Tobias
authors.initials: T
authors.lastname: Kunstmann
authors.forename: Markus
authors.initials: M
authors.lastname: Fendrich
authors.forename: Rolf
authors.initials: R
authors.lastname: Möller
authors.forename: Marika
authors.initials: M
authors.lastname: Schleberger