Berlin 2012 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 27: Half-metals and Oxides (jointly with TT)
MA 27.10: Vortrag
Mittwoch, 28. März 2012, 12:00–12:15, EB 202
Giant spontaneous magnetostriction in FeTiO3: effects of repulsive dipole-dipole interactions — •Michalis Charilaou1,2, Denis Sheptyakov3, Jörg F Löffler2, and Andreas U Gehring1 — 1Earth and Planetary Magnetism, Department of Earth Sciences, ETH Zurich, 8092 Zurich, Switzerland — 2Metal Physics and Technology, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland — 3Laboratory for Neutron Scattering, Paul Scherrer Institute, 5232 Villigen, Switzerland
We present neutron diffraction data and magnetic susceptibility measurements of FeTiO3 ilmenite at temperatures of 1.9 K < T < 300 K. The magnetic susceptibility shows typical antiferromagnetic behavior with a long-range ordering at the Néel temperature TN = 58(1) K. The magnetic peaks of the neutron diffraction patterns reveal a canted antiparallel spin configuration along the c axis of the R-3 structure. The lattice dimensions decrease with decreasing temperature, but upon the onset of order the c-dimension grows strongly, and at T = 1.9 K exhibits a spontaneous magnetostriction of 2.46(9) 10−3. The observations are interpreted as the result of repulsive dipole-dipole interactions between neighboring Fe-rich layers and the onset of spin-orbit coupling at TN.