Departmental Papers (MEAM)

Document Type

Journal Article

Date of this Version

November 2004


Copyright (2004) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. Reprinted in Applied Physics Letters, Volume 85, Issue 20, November 2004, pages 4738-4740.

NOTE: At the time of publication, author Robert W. Carpick was affiliated with the University of Wisconsin. Currently (June 2007), he is a faculty member in the Department of Mechanical Engineering and Applied Mechanics at the University of Pennsylvania. Publisher URL:


The phase shift in amplitude-controlled dynamic atomic force microscopy (AFM) is shown to depend on the cantilever-sample tilt angle. For a silicon sample and tip the phase shift changes by nearly 15º for a change in tilt angle of 15º. This contribution to the phase results from the oscillating tip's motion parallel to the surface, which contributes to the overall energy dissipation. It occurs even when the measurements are carried out in the attractive regime. An off-axis dynamic AFM model incorporating van der Waals attraction and a thin viscous damping layer near the surface successfully describes the observed phase shifts. This effect must be considered to interpret phase images quantitatively. © 2004 American Institute of Physics.


silicon, elemental semiconductors, atomic force microscopy, damping



Date Posted: 22 June 2007

This document has been peer reviewed.