Regensburg 2004 – scientific programme
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MA: Magnetismus
MA 3: Anisotropie / Magnetoelastizit
ät
MA 3.3: Talk
Monday, March 8, 2004, 12:30–12:45, H10
Strong change of the crystal structure of Tb0.5Dy0.5Cu2 induced by an external magnetic field — •Sebastian Raasch1,2, Mathias Doerr1, Martin Rotter3, Andreas Kreyssig1, Jens-Uwe Hoffmann2, Ulrike Witte1,2, and Michael Loewenhaupt1 — 1TU Dresden, Institut fuer Festkoerperphysik, Germany 01062 Dresden — 2Hahn Meitner Institut Berlin — 3Universitaet Wien, Institut fuer physikalische Chemie
Magnetic fields of 4 T applied to a single crystal Tb0.5Dy0.5Cu2 along the (magnetic hard) c axis affect a change of the crystalline structure. Concurrently the symmetry axes change. Neither decreasing the magnetic field to zero nor warming up the crystal to room temperature led to a virgin state crystal. Further a change of the magnetic anisotropy has been observed. This behaviour, which was also observed at similar orthorhombic RCu2 (R = Rare Earth) compounds, can not be explained only by a competition of single ion and exchange anisotropy.
In our recent neutron-scattering experiment at the E2 flat cone diffractometer of the HMI Berlin we proved, that this structural conversion is associated with the decay of the single-domain crystal into three (crystallographic) variants, rotated by 60 degrees within the pseudo hexagonal ac-plane. Models of the converted crystal structure are compared to the results of the experiment.