Berlin 2012 – wissenschaftliches Programm
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KR: Fachgruppe Kristallographie
KR 6: 100 years since the Laue experiment: Topical aspects of diffraction and scattering (Joint Session KR, BP, DF, GP, MA, MI, MM; related to SYXD)
KR 6.8: Vortrag
Dienstag, 27. März 2012, 11:45–12:00, EMH 225
Magnetic structure of magnetoelectric NdFe3(BO3)4 under applied magnetic fields — •Jorge E. Hamann-Borrero1, Sven Partzsch1, Sergio Valencia2, Claudio Mazzoli3, Christian Hess1, A. Vasiliev4, L. Bezmaternikh5, Bernd Büchner1, and Jochen Geck1 — 1IFW-Dresden — 2Helmholtz-Zentrum-Berlin — 3ESRF, Grenoble, France — 4Moscow State University, Russia — 5L. V. Kirensky Institute of Physics, Russian Academy of Sciences, Krasnoyarsk, Russia
The magnetic structure of the magneto-electric NdFe3(BO3)4 is studied by means of Resonant X-ray Magnetic Scattering (RXS) at the Nd L2,3 and Fe K edges. The temperature dependent experiments show below TN = 30 K the appearance of commensurate (CM) magnetic superlattice reflections with Miller indices (0,0,l± 3/2) (where l=3n and n= integer). By further cooling, at TICM∼ 16 K, a transition into an incommensurate (ICM) spin helix structure is observed in agreement with recent neutron experiments[1,2]. Detailed mean field based analysis of the x-ray diffracted intensities show, that the Nd and Fe magnetic sublattices behave differently. In fact the magnetization of the Nd sublattice is induced by the Fe moments.
At T<TICM, by applying an external magnetic field B parallel to the ab-plane, the magnetic structure suffers a reorientation transition from a spin helix configuration to a collinear structure where all the moments align perpendicular to B in the basal plane.
[1] M. Janoschek et al. Phys. Rev. B, 2010, 81, 094429
[2] P. Fischer et al. Jour. Phys. Cond. Matt., 2006, 18, 7975-7989(15)