Berlin 2015 – scientific programme
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O: Fachverband Oberflächenphysik
O 101: Scanning Probe Techniques: AFM
O 101.6: Talk
Friday, March 20, 2015, 11:45–12:00, MA 144
The contact charging of insulators by atomic force microscopy — •Monika Mirkowska1, 2, Markus Kratzer1, Stefan Klima1, 2, Helmut Flachberger2, and Christian Teichert1 — 1Institute of Physics, Montanuniversität Leoben, Austria — 2Chair of Mineral Processing, Montanuniversität Leoben, Austria
Better understanding of tribocharging and contact electrification of dielectric materials is of great interest for technological applications like tribocharging separation of mineral particles and secondary raw materials. The underlying mechanisms are still not well understood. The charging of calcite single crystal surfaces upon contact with an Atomic Force Microscope (AFM) tip and micrometer sized single calcite particles attached to the end of commercial AFM cantilevers has been investigated using Kelvin Probe Force Microscopy (KPFM). The resulting surface charge depends on the type of charging (static charging, matrix of static charging, rubbing), the load force, and the value of the initial surface potential. A charge decay, within several tens of hours, has been observed. Increasing the sample temperature accelerated this charge decay process. Sequential charging of the same area with opposite sign could be performed, showing that the preceding charging does not alter the charging behavior.Experiments were carried out under various conditions.