Dresden 2009 – wissenschaftliches Programm
TT 17.3: Vortrag
Dienstag, 24. März 2009, 14:30–14:45, HSZ 03
Polarized neutron tomography of Ni3Al and Fe2TiSn — •Andreas Neubauer1, Michael Schulz1, Christian Pfleiderer1, Peter Böni1, Anke Köhler2, Nadja Wizent2, and Günther Behr2 — 1Physik Department E21, Technische Universität München, D-85748 Garching, Germany — 2Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden, PF270116, 01171 Dresden, Germany
The transition metal compounds Ni3Al and Fe2TiSn are weakly ferromagnetic metals, for which the magnetic properties are extremely sensitive to composition. We have attempted the growth of polycrystalline and single-crystal rods of these compounds with an UHV compatible image furnace. The polycrystalline starting material as well as the floating-zoned rods have been characterized by means of conventional bulk properties and EDX. As a new method we have additionally carried out polarized neutron tomography. The depolarization of the neutron beam proves to be extremely sensitive to tiny variations of the ferromagnetic transiton temperature, thus providing key information on the metallurgical phase diagram and the ideal growth conditions. The possible implications of our observations for the nature of quantum criticality in these compounds will be discussed.