Dresden 2014 – scientific programme

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DF: Fachverband Dielektrische Festkörper

DF 10: Dielectric surfaces and interfaces

DF 10.2: Talk

Wednesday, April 2, 2014, 09:50–10:10, GER 37

Exploring contact charging of single crystalline dielectrics by atomic force microscopy — •Monika Mirkowska^1,2, Markus Kratzer², Stefan Klima^1,2, Helmut Flachberger¹, and Christian Teichert² — ¹Chair of Mineral Processing, Department Mineral Resources and Petroleum Engineering, Montanuniversität Leoben, Austria — ²Institute of Physics, Montanuniversität Leoben, Austria

The electrostatic charging of surfaces is successfully applied in the triboelectrostatic separation of mineral particles. However, the knowledge about the charge exchange during the insulator-insulator contact is still limited. Here, we study the electric charging of well-defined dielectric surfaces (quartz and calcite single crystals) upon contact with conventional atomic force microscopy (AFM) probes and with micrometer sized single calcite particles attached to the end of commercially available AFM cantilevers. We examined the effect of different contact types like static contact, point charging, and rubbing on the charging. A combination of contact mode atomic force microscopy (for charging) and Kelvin probe force microscopy was applied in order to verify the local electrostatic potentials of the surfaces before and after charging. Special attention was put on the influence of humidity (adsorbed water layer), contact time and load force on the charge transfer.