Regensburg 2002 – wissenschaftliches Programm
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MA: Magnetismus
MA 8: Hart- und Weichmagn. Materialien / Legierungen
MA 8.7: Vortrag
Dienstag, 12. März 2002, 15:15–15:30, H10
Magnetic properties of melt spun ribbons of DyFe6Al6 — •Peter Kerschl1, Bogdan Idzikowski1,2, Ulrich K. Rößler1, Konstantin Nenkov1, Dieter Eckert1, Karl-Hartmut Müller1, and Ludwig Schultz1 — 1IFW Dresden, Helmholtzstrasse 20, 01069 Dresden — 2Institute of Molecular Physics, Polish Academy of Sciences, M. Smoluchowskiego 17, PL60-179 Poznan, Polen
We have prepared melt spun ribbons of the compound
DyFe6Al6 isostructural to the tetragonal ThMn12 structure. The
samples appear
to be single phase already in as quenched state according
to X-ray diffraction pattern. For the magnetic measurements,
a commercial SQUID and the pulsed field magnetometer of
the IFW Dresden were used. Due to the interplay of
the localised magnetic moment of the heavy rare earth
dysprosium and the itinerant moment of iron, the total
magnetic appearance differs drastically from
the Curie-Weiss behaviour. There are two magnetic transitions:
the ferrimagnetic ordering with Curie temperature of
about 350 K, and another of unknown nature at lower temperature
of about 150 K. In this temperature range, thermal hysteresis
indicates spin freezing with disorder. In the low-temperature
state we do not find saturation in pulsed magnetic fields up
to 40 T indicating very strong antiferromagnetic couplings.
Magnetoresistance was measured in fields up to 5 T with
sizeable effects only in the ferrimagnetic high-temperature
state and strong dependence on temperature-field pre-history.
This work is supportet by BMBF project: 03 SC 5 DRE.