Regensburg 2004 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 24: Postersitzung III: Korrelierte Elektronen, ”Orbital Physics”
TT 24.32: Poster
Mittwoch, 10. März 2004, 14:30–19:00, Poster A
Investigation of the Low Ordered Moment in CeBiPt — •G. Goll1, O. Stockert2, M. Prager3, N. Stüßer4, and T. Takabatake5 — 1Physikalisches Institut, Universität Karlsruhe, 76128 Karlsruhe — 2Max-Planck-Institut CPfS, 01187 Dresden — 3Institut für Festkörperforschung, Forschungszentrum Jülich, 52425 Jülich — 4Hahn-Meitner-Institut, 14109 Berlin — 5Department of Quantum Matter ASDM, Hiroshima University, Higashi Hiroshima, 739-8526, Japan
The electronic properties of CeBiPt show semimetallic behavior with low charge carrier concentration nh= 7.7 · 1017 cm−3. Shubnikov-de Haas experiments reveal a Fermi surface consisting mainly of a small hole pocket around the Γ point with a volume of 1.5 · 10−4 of the volume of the first Brillouin zone [1]. To explain these result by band-structure calculation a local character of the 4f electrons is required. The magnetic behavior supports a local character as well. The magnetic susceptibility follows a Curie-Weiss law above T=100 K with the full moment of free Ce3+ ions and magnetic order was found below TN=1.1 K by specific-heat measurements [2]. However, previous neutron-diffraction data suggested an ordered moment well below 1 µB. Crystal-electric fields (CEF) in the cubic crystal symmetry can only partly account for the reduced moment. Inelastic neutron scattering as well as neutron diffraction on powder were used to investigate the CEF ground state and the magnetically ordered moment. The measurements suggest additional magnetic excitations with a characteristic temperature of 10 - 20 K being responsible for the low ordered moment.
[1] G. Goll et al., Europhys. Lett. 57, 233 (2002).
[2] T. Pietrus et al., Physica B 281 & 282, 745 (2000).