Berlin 2008 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 3: Magnetic Semiconductors
MA 3.7: Vortrag
Montag, 25. Februar 2008, 11:45–12:00, H 1012
Induced Ferromagnetic Order at Room Temperature in (Ga,Mn)As — F. Maccherozzi1, •M. Sperl2, G. Panaccione2, M. Hochstrasser3, G. Rossi1,4, J. Minár5, S. Polesya5, H. Ebert5, U. Wurstbauer2, G. Woltersdorf2, W. Wegscheider2, and C. H. Back2 — 1Laboratorio Nazionale TASC, INFM-CNR, in Area Science Park, S.S. 14, Km 163.5, I-34012, Trieste, Italy — 2Institut für Experimentelle Physik, Univ. Regensburg, D-93040 Regensburg, Germany — 3Laboratorium für Festkörperphysik, Wolfgang-Pauli-Strasse 16, ETH Hönggerberg, CH-8093 Zürich, Switzerland — 4Dipartimento di Fisica, Univ. di Modena e Reggio Emilia, Via A. Campi 231/A, I-41100, Modena, Italy — 5Department of Chemistry, Ludwig-Maximilians University Munich, Germany
The low Curie temperature of Diluted Ferromagnetic Semiconductors (DMS) has been an obstacle for the integration of DMS into electronic prototypes. Here we demonstrate that this disadvantage can be overcome by using ferromagnetic proximity polarization. We show that a thin layer of (Ga,Mn)As can be spin polarized at room temperature by the proximity to an iron layer. X-ray magnetic circular dichroism and superconducting quantum interference device magnetometry are used to study magnetic order in the iron film and in (Ga,Mn)As film. We conclude that the induced magnetic order in the (Ga,Mn)As layer extends over more than 2 nm, even at room temperature. Furthermore, we show by experiment as well as by theory that the magnetic moment of the Mn ions couples antiferromagnetically to the moment of the Fe layer.