Dresden 2006 – wissenschaftliches Programm
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MA: Magnetismus
MA 17: Magnetic Materials II
MA 17.7: Vortrag
Dienstag, 28. März 2006, 11:45–12:00, HSZ 401
Microscopic magnetism of the multiferroic spinel CdCr2S4 — •E. Goering1, S. Gold1, J. Deisenhofer2, J. Hemberger2, V. Tsurkan2, and A. Loidl2 — 1MPI für Metallforschung, 70569 Stuttgart — 2Institiut für Korrelationen und Magnetismus, Uni-Augsburg, 86135 Augsburg
The coexistence of ferromagnetism and ferroelectricity, has recently attracted much interest in perovskite rear earth manganites [1]. This is connected to a possible new generation of promising electronic devices, where electronic polarization and magnetism are coupled to each other. For CdCr2S4 a colossal magnetocapacitive coupling has been observed close to the ferromagnetic ordering temperature of about [2]. We will show here X-ray magnetic circular dichroism results at the Cr L2,3 edges performed at 33K and 1T external magnetic field, in order to investigate the microscopic magnetic properties of CdCr2S4. The magnetic spectra exhibit unusual and very complex structures (see figure). By the use of sum rules and a self consistent j3/2 j1/2 mixing correction a slightly reduced, compared to the bulk value of 3*B [2], spin moment of 2.2*B has been found. The orbital moment exhibits a nearly vanishing value of 0.037*B, consistent to the theoretically predicted high spin configuration with fully occupied majority t2g orbitals.
[1] T. Kimura, et al.; Nature 426 (2003) 55. T. Goto, et al.; Phys. Rev. Lett 92 (2004) 257201 [2] J. Hemberger, et al.; Nature 434 (2005) 364.