Neutron and Synchrotron-Diffraction Study of UPtGe
UPtGe has an incommensurate and non-collinear magnetic structure. Neutron experiments on a single crystal have shown that the crystal structure is neither the TiNiSi nor disordered CeCU(2) type, as previously suggested, but rather the noncentrosymmetric EuAuGe structure, with two independent uranium atoms in the asymmetric unit. We report details of the cycloidal magnetic structure as examined by a conventional diffractometer, and the neutron polarimeter at the Institut Laue Langevin. The uranium moments are different on the two sites, with the average value of 1.4JLB. A single magnetic domain exists and we believe this is a consequence of the noncentrosymmetric crystal structure. As a result the crystal produces a polarized beam of neutrons from an incident unpolarized beam. In resonant scattering experiments at the ID20 beam line of the ESRF the second-order magnetic satellite, which is a direct consequence of the cycloid structure and the resonant cross section, was observed with the photon energy tuned to the uranium M 4 edge. The ratio of this to the first-order satellite is more than an order of magnitude less than that found in similar experiments on Ho. We have also observed weak resonant effects at the Pt L3 and Ge K edges.
Bibliographic Reference: Article: Physical Review B vol.62, no.6(2000) pp 3801-3810
Record Number: 200012819 / Last updated on: 2000-11-03
Original language: en
Available languages: en