Dresden 2009 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 3: Magnetic Half Metals and Oxides

MA 3.1: Vortrag

Montag, 23. März 2009, 11:00–11:15, HSZ 401

Magneto-optical study of Co₂-based Heusler compound thin films — •Simon Trudel, Jaroslav Hamrle, Oksana Gaier, Thomas Sebastian, and Burkard Hillebrands — FB Physik and Forschungszentrum OPTIMAS, TU Kaiserslautern, 67663 Kaiserslautern, Germany

Co₂-based Heusler compounds are promising materials for spintronic applications due to their predicted half-metallicity, their high Curie temperatures, and their tunable magnetic properties with respect to composition.

In this presentation, we will present our recent results on the magnetic characterization of Co₂-based Heusler compound thin films using magneto-optical probes such as magneto-optical Kerr effect (MOKE) and Brillouin light scattering (BLS) spectroscopy.

In our MOKE investigations, we particularly focus on the amplitude of the longitudinal (LMOKE) and quadratic MOKE (QMOKE) signals. We find that for several Co₂-based Heusler alloys, the QMOKE signal is remarkably strong. This points to an important contribution from second-order (and higher) spin-orbit interaction in this family of materials.

Using BLS spectroscopy, we find that the exchange constant of Co₂-based compounds depends on their composition. In particular, the exchange constant and the spin-wave exchange stiffness increase with the concentration of valence electrons.

Financial support from DFG FG559 “Neue Materialien mit hoher Spinpolarization" is gratefully acknowledged.