Dresden 2009 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 13: Poster Ia: Electron Theory (1); Magnetic Imaging (2,3); Thin Films (4-25); MSMA (26-33); Magn. Semiconductors (34-42); Magn. Half Metals and Oxides (43-60)

MA 13.43: Poster

Dienstag, 24. März 2009, 10:15–13:00, P1A

Suppression of resistivity due to thermal treatment of SnO₂ thin films — •Ali Awada¹, Dirk Menzel¹, Joachim Schoenes¹, Frank Ludwig², and Meinhard Schilling² — ¹Institut für Physik der Kondensierten Materie, TU Braunschweig, Germany — ²Institut für Elektrische Messtechnik und Grundlagen der Elektrotechnik, TU Braunschweig, Germany

In the field of diluted magnetic semiconductors, transition metal doped oxides have attracted much interest because of a Curie temperature which is beyond 300 K. Among these materials SnO₂ is a promising host material for spintronic applications due to its low electrical resistivity despite a high optical transparency. Conductivity measurements of sputtered SnO₂ thin films show a resistivity in a wide range from 0.2 to 80 Ωcm at room temperature depending on the preparation parameters. The stoichiometry of the SnO₂ plays a crucial role since the conductivity of the tin dioxide is presumably determined by donor levels originating from oxygen vacancies [1]. In order to exert influence on the amount of defects the films were annealed after deposition. In comparison to the as-grown samples a suppression of the resistivity due to the thermal treatment by a factor of more than 10 is observed. Since it is assumed that the ferromagnetic exchange is mediated via free charge carriers in the sense of a magnetic polaron the tuning of the electrical properties is a key issue towards diluted magnetic semiconductors with large ordered moments and high Curie temperatures.

[1] D. Menzel, A. Awada, H. Dierke, J. Schoenes, F. Ludwig, and M. Schilling, J. Appl. Phys. 103, 07D106 (2008).