Dresden 2009 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 47: Methods: Scanning probe techniques II

O 47.5: Vortrag

Donnerstag, 26. März 2009, 11:30–11:45, SCH A316

Distance and material dependence of the near-field thermal heat transfer — •Robert Berganski, Achim Kittel, and Uli F. Wischnath — Energy and Semiconductor Research Laboratory - University of Oldenburg

The heat transfer between the probe and the sample is measured by means of a Near-field Scanning Thermal Microscope (NSThM) which is based on a commercial scanning tunneling microscope. In our setup the standard STM-Probe is replaced by a miniaturized coaxial thermocouple, which records the change in the temperature at the tip. Thus the heat transfer can be measure while the distance between the probe and the sample surface will be varied by a few tens nanometers. The investigated heat transfer relies on evanescent modes of the thermal transfer between the tip at room temperature and the sample at about 110K. All other interfering distant dependent heat transfer mechanisms are excluded by using ultra high vacuum conditions. In the present contribution the focus lies on the material dependence of these evanescent modes which are reaching a few nanometers into the vacuum. The influence of the dielectric properties of the sample material on the heat transfer is studied by varying the material of the sample surface.