title: A subsurface add-on for standard atomic force microscopes.
abstract: The application of ultrasound in an Atomic Force Microscope (AFM) gives access to subsurface information. However, no commercially AFM exists that is equipped with this technique. The main problems are the electronic crosstalk in the AFM setup and the insufficiently strong excitation of the cantilever at ultrasonic (MHz) frequencies. In this paper, we describe the development of an add-on that provides a solution to these problems by using a special piezo element with a lowest resonance frequency of 2.5 MHz and by separating the electronic connection for this high frequency piezo element from all other connections. In this sense, we support researches with the possibility to perform subsurface measurements with their existing AFMs and hopefully pave also the way for the development of a commercial AFM that is capable of imaging subsurface features with nanometer resolution.
authors.affiliation: JARA-FIT and II. Institute of Physics, RWTH Aachen University, 52074 Aachen, Germany.
authors.forename: G J
authors.initials: GJ
authors.lastname: Verbiest
authors.affiliation: Kamerlingh Onnes Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands.
authors.forename: D J
authors.initials: DJ
authors.lastname: van der Zalm
authors.affiliation: Kamerlingh Onnes Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands.
authors.forename: T H
authors.initials: TH
authors.lastname: Oosterkamp
authors.affiliation: Kamerlingh Onnes Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands.
authors.forename: M J
authors.initials: MJ
authors.lastname: Rost