Berlin 2015 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 32: Spin Structures and Magnetic Phase Transitions
MA 32.4: Vortrag
Mittwoch, 18. März 2015, 15:45–16:00, EB 202
Neutron study of the field-dependant spin structure of nanocrystalline and coarse-grained holmium — •Daniel Kaiser1, Philipp Szary1, Jens-Peter Bick1, Andre Heinemann2, Charles Dewhurst3, and Andreas Michels1 — 1Physics and Materials Science Research Unit, University of Luxemburg — 2HZG, Geesthacht, Germany — 3Institute Laue-Langevin, Grenoble, France
We present the results of magnetic-field-dependant small-angle neutron scattering (SANS) measurements on nanocrystalline (nc) and coarse-grained (cg) polycrystalline holmium. At 50 K, single-crystalline holmium exhibits a series of complicated spin structures with increasing applied magnetic field, ranging from a simple antiferromagnetic helix, to a helifan-3/2, to a fan, and finally to a ferromagnetic structure. While the transitions between these different structures are discrete in the defect-free single-crystalline case, we observe for nc and cg holmium the emergence of periodic structures with a continuously changing wavelength. Moreover, a superposition of several structures at the same field was found for both materials.