Regensburg 2007 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

MA: Fachverband Magnetismus

MA 22: FV intern Symposium: "Heusler Alloys"
Invited Talks Kübler/Yamamoto/Inomata/Silvia Picozzi

MA 22.5: Vortrag

Donnerstag, 29. März 2007, 12:15–12:30, H10

Huge magneto-optical Kerr effect and its modification by ion irradiation in the Co₂FeSi Heusler compound — •J. Hamrle¹, O. Gaier¹, S. Blomeier¹, H. Schneider², G. Jakob², B. Reuscher³, A. Brodyanski³, M. Kopnarski³, C. Felser⁴, and B. Hillebrands¹ — ¹FB Physik and Forschungsschwerpunkt MINAS, TU Kaiserslautern, E.-Schrödinger-Str. 56, D-67663 Kaiserslautern — ²Institut für Physik, J.-Gutenberg-Universität, Staudinger Weg 7, D-55128 Mainz — ³IFOS TU Kaiserslautern, E. Schrödinger-Str. 56, D-67663 Kaiserslautern — ⁴Institute of Chemistry, J.-Gutenberberg-Universität, Staudingerweg 9, D-55128 Mainz

Heusler alloys are promising candidates for spintronics devices providing 100% spin polarization. We report on magnetic and magneto-optical properties of thin Co₂FeSi (CFS) Heusler films measured by means of magneto-optical Kerr effect (MOKE). CFS films sputtered on MgO(100) grow in the fully ordered L2₁ structure. MOKE hysteresis loops measured on CFS films exhibit a large quadratic (QMOKE) and longitudinal MOKE (LMOKE) contribution, resulting in asymmetrical MOKE loops. The amplitude of the QMOKE is 30 mdeg, the largest QMOKE found so far. It is a hint of an unusually large second-order spin-orbit (SO) coupling in CFS films. We studied the effect of structural disorder on the magnetic properties by irradiating the CFS samples with different fluences of 30 keV Ga⁺ ions. Results shows that small doses reduce the second-order SO coupling while keeping unmodified the first order SO coupling. Supported by the DFG in the FG 559 and by the Japanese government in the NEDO 2004IT093.