Regensburg 2016 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MA: Fachverband Magnetismus
MA 41: Magnetic Coupling Phenomena
MA 41.8: Vortrag
Donnerstag, 10. März 2016, 11:30–11:45, H33
Magneto-electronic coupling in modulated defect-structures of natural Fe1−xS — •Dimitrios Koulialias1,2, Jörg F. Löffler2, Andreas U. Gehring1, and Michalis Charilaou2 — 1Institute of Geophysics, Department of Earth Sciences, ETH Zurich — 2Laboratory of Metal Physics and Technology, Department of Materials, ETH Zurich
Pyrrhotite (Fe7S8) is a major magnetic remanence carrier in the Earth’s crust and in extraterrestrial materials, and its magnetic and electronic properties have initiated a large number of experimental and theoretical studies since more than a century. Despite the intense research efforts, there is still a lack of understanding of the low-temperature transition that is observed in natural samples. Importantly, it is not known whether the origin of the transition is structural or magnetic. We will provide compelling evidence that the low-temperature transition is a phenomenon caused by magnetic coupling between epitaxially intergrown superstructures. The two superstructures differ in their defect distribution, and consequently in their magnetic anisotropy. At T < 30 K, the magnetic moments of the superstructures become strongly coupled, resulting in a 12-fold anisotropy symmetry, which is reflected in the anisotropic magnetoresistance.