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 13.46: Poster
Dienstag, 24. März 2009, 10:15–13:00, P1A
Searching for Intrinsic Magnetic Order in Pure ZnO Thin Films — •M. Khalid1, M. Ziese1, A. Setzer1, P. Esquinazi1, H. Hochmuth2, M. Lorenz2, M. Grundmann2, D. Spemann3, and T. Butz3 — 1Division of Superconductivity and Magnetism — 2Semiconductor Physics Group — 3Division of Nuclear Solid State Physics — Faculty of Physics and Geosciences, University of Leipzig, 04103 Leipzig.
Defect-induced room temperature ferromagnetism in oxide semiconductors has attracted wide research interest in recent years. In view of their potential spintronic and optoelectronic properties we studied the magnetic properties of pure ZnO films grown under reducing conditions. The films were grown by pulsed laser deposition onto Al2O3 (1120) substrates. Substrate temperature was between room temperature and 570∘C and N2 partial pressure between 0.007 mbar and 0.3 mbar. The magnetic properties of the bare substrates and the ZnO films were investigated by SQUID magnetometry. The samples were directly clamped in straws for magnetization measurements to minimize spurious magnetic signals from the sample mounting. The Al2O3 substrates showed a small residual ferromagnetic-like contribution. None of the ZnO films showed reproducible ferromagnetic hysteresis significantly larger than the substrates. The purity of the ZnO films was checked by particle induced X-ray emission and iron contamination between 30 and 200 µg iron per gram ZnO was detected. In conclusion, ZnO films grown under reducing N2 atmosphere did not show any reproducible ferromagnetic contribution to the SQUID signal.