Dresden 2017 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 67: Poster 4

MA 67.20: Poster

Freitag, 24. März 2017, 09:30–13:00, P2-OG3

Calorimetric Experiments on Fe/W(110) using SP-STM — •Hermann Osterhage, Cody Friesen, and Stefan Krause — Universität Hamburg, Department of Physics, Jungiusstrasse 11A, 20355 Hamburg, Germany

The Seebeck effect provides the possibility to use waste heat to drive electric devices. Combined with progressing miniaturisation this offers a chance to increase the efficiency of future circuits.

In our experiment, we use spin-polarized scanning tunneling microscopy (SP-STM) to investigate the magneto-Seebeck tunneling on a very local scale. While the sample is at a temperature of T = 50  K, we heat the SP-STM tip by laser irradiation. The resulting thermovoltage between tip and sample is countered by an external bias, yielding zero tunneling current [1]. From the theoretical model of the tunneling process in STM, a proportionality between thermovoltage and tip-sample separation is expected [2]. Experimental results on the Fe/W(110) surface will be shown and compared to this model in terms of the tip-sample separation dependent thermovoltage, and the temperature difference between tip and sample.

[1] D. Hoffmann et al., J. Electron. Spectrosc. Relat. Phenom. 109, 117 (2000).

[2] J. A. Støvneng et al., Phys. Rev. B 42, 9214 (1990).