Dresden 2009 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 40: Poster II: Bio- and Molecular Magnetism (1-9); Magnetic Coupling Phenomena/Exchange Bias (10-15); Magnetic Particlicles and Clusters (16-29); Micro and Nanostructured Magnetic Materials (30-51); Multiferroics (52-64); Spin Injection in Heterostructures (65-67); Spin-Dyn./Spin-Torque (68-93); Spindependent Transport (94-108)
MA 40.38: Poster
Freitag, 27. März 2009, 11:00–14:00, P1A
Preparation and characterization of Ni2MnIn Heusler electrodes for spin valves — •Hauke Lehmann, Jan M. Scholtyssek, Jeannette Wulfhorst, Ulrich Merkt, and Guido Meier — Institut für Angewandte Physik und Zentrum für Mikrostrukturforschung, Universität Hamburg, Jungiusstr. 11, 20355 Hamburg
We grow Ni2MnIn films by thermal coevaporation of Ni and the alloy MnIn. The films are deposited on Si3N4 membranes for transmission-electron microscopy (TEM) as well as on Si, SiO2, and Si3N4 for investigations of the electronic structure. We determine the transport spin polarization by point-contact Andreev reflection spectroscopy (PCAR) [1]. The resistivity of the films is measured using a four-terminal van der Pauw setup. Nanopatterned Ni2MnIn Heusler electrodes for spin-valve structures are prepared by electron-beam lithography. As a first test, the anisotropic magnetoresistance (AMR) of each individual electrode is measured. In a further step we want to investigate the spin-valve effect of the whole structure. In view of the temperature-sensitivity of the electron-beam resist, the electrodes are grown at low temperature and annealed afterwards. The post-growth annealing process is investigated in situ in the TEM using transmission-electron diffraction on films grown on Si3N4 membranes [2]. The change of the resistivity during the annealing process is analyzed.
[1] L. Bocklage, J. M. Scholtyssek, U. Merkt, and G. Meier,
J. Appl. Phys. 101, 09J512 (2007)
[2] J. M. Scholtyssek, G. Meier, and U. Merkt,
J. Crystal Growth accepted (2008)