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Magnetismus Poster: Do., 13:00–15:30 D-P250
Magnetic Ordering in Multiferroic DyMnO3
O Prokhnenko 1 , S. Landsgesell 1 , D. Argyriou 1 , L.C. Chapon 2
1 Hahn-Meitner-Institut, Glienicker Str. 100, Berlin D-14109, Germany – 2 ISIS Facility,
Rutherford Appleton Laboratory-CCLRC, Chilton, U.K.
DyMnO3 belongs to the family of the spin frustrated multiferroic perovskites which
exhibit a strong coupling between magnetism and ferroelectricity. We have examined
the magnetic and crystal structure of 163 DyMnO3 using neutron powder diffraction.
We find that the Mn-spins order incommensurately with propagation vector
q = (0, δ, 0), δ ∼ 0.37 at T > TN (Mn)=38 K. The magnitude of δ varies as a function
of temperature much the same way as it does in TbMnO3. At lower temperature,
TN (Dy) ∼6 K, we find that Dy spins order commensurately with propagation
vectorq = (0, 1/2, 0), while the ordering of Mn-spins remain incommensurate.
Surprisingly we find that as Dy-spins order the intensity of reflections that arise from
Mn ordering decrease substantially in intensity. This may imply that Dy-spins also
order with the same wavevector as Mn-spins and contributed to the corresponding
Bragg reflections for T>TN (Dy). This hypothesis has been confirmed my resonant
X-ray scattering presented in an other contribution to this conference.