Influence of volume and surface properties on phase contrast in tapping mode atomic force microscopy

Phase imaging angle of the cantilever oscillation in tapping mode scanning force microscopy can be related to the energy dissipated per oscillation. Nevertheless, in many cases, the physical properties (adhesion, viscosity...) of the sample that are sources of this energy dissipation are not clearly identified. We propose a simple method to distinguish the influence of surface and volume properties on phase imaging. This method is based on equalizing of surface properties by covering the sample surface with thin gold layers. As an example, in our specific working conditions (moderate tapping on glass-polyester composite), we show that volume properties have an important influence on the phase signal in comparison to surface properties. (C) 2002 Elsevier Science B.V. All rights reserved.