Regensburg 2010 – scientific programme
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O: Fachverband Oberflächenphysik
O 34: Methods: Scanning probe techniques IV
O 34.5: Talk
Tuesday, March 23, 2010, 16:00–16:15, H32
A calibration device for Scanning Thermal Microscopy based on the 3-ω-method — •Uli F. Wischnath, Adrian Czicholewski, and Achim Kittel — Energy and semiconductor research, Dept. of Physics, Univ. Oldenburg, 26111 Oldenburg
Near-field Scanning Thermal Microscopy (NSThM) measures the heating or cooling of a probe tip by a sample for distances of up to some nm [1]. The tip temperature has to be linked to theoretically calculated values of the heat flow for comparison with the theory of thermal near-field radiation.
We have constructed a calibration device for this purpose, consisting of a 4 µm thick glass fiber of about 5 mm length bridging two banks. The banks and the fiber are evaporated with a 80 nm thin metal film forming the heat source for the 3ω-method. The glass fiber has to be considered for the thermal properties while it merely serves as a passive support concerning the electrical properties. The thermal resistances for such composites are determined with the 3ω method to be of the order of 106 K/W. This value would not be accessible with a metal wire of sufficient mechanical stability.
A NSThM brought into tunneling distance forms an additional heat sink. The alteration of the 3ω signal is then used to quantify the heat flow corresponding to the thermovoltages.
[1] U. F. Wischnath, J. Welker, M. Munzel, and A. Kittel, Rev. Sci. Instrum.79, 073708, 2008.