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MA: Fachverband Magnetismus
MA 18: Spin Structures and Magnetic Phase Transitions
MA 18.3: Vortrag
Mittwoch, 25. März 2009, 10:45–11:00, HSZ 401
Diffuse neutron scattering of interesting phases in Dy2Ti2O7 — •Jonathan Morris1, Alan Tennant1,2, Santiago Grigera3,4, Kirrily Rule1, and Bastian Klemke1 — 1Helmholtz-Zentrum Berlin for Materials and Energy, Glienicker Str. 100, 14109 Berlin, Germany. — 2Institut fur Festkorperphysik, Technische Universitat Berlin, Hardenbergstr. 36, Berlin 10623, Germany. — 3St. Andrew's University, St. Andrews, Scotland — 4Instituto de Física de Líquidos y Sistemas Biológicos, La Plata, Argentina
The prospect of observing emergent magnetic monopoles in spin-ice has recently increased the interest in these systems [1]. Dy2Ti2O7 is a effective spin-1/2 pyrochlore which is a clean model frustrated system where interesting physics may be observed and compared with theory.
Here we present new neutron measurements from E2 at the Helmholtz-Zentrum Berlin which show an agreement with spin-ice correlation functions at 0.7K and 0T, and a complex Q-dependent diffuse scattering at fields below the saturation field along [100]. These are being understood in the context of spin-strings, or spin-random-walks, which are the prerequisite for monopoles. The scattering allows us to follow the development of these strings with field and provides new insight into the Kastelyn physics within this pyrochlore.
[1] "Magnetic monopoles in spin ice" C. Castelnovo, R. Moessner & S. L. Sondhi. Nature 451, 42-45 (3 January 2008)