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Abstract

Neutron and resonant x-ray magnetic scattering studies have been performed on single crystals of three compositions, x = 0.25, 0.50, and 0.75 of the (U(1)�(x)Pu(x))Sb solid solution. Neutron diffraction has established the ordering wave vector, the average magnetic moment, and the temperature dependence of the magnetic order. For the x = 0.75 sample the presence of a third-order harmonic indicates a substantial squaring of the 4+, 4� magnetic configuration. The resonant x-ray magnetic scattering experiments have been performed at the U M(4) (3.728 keV) and Pu M(4) (3.963 keV) edges, exploiting the element-specific nature of this probe. For the x = 0.50 sample, conventional long-range magnetic order is found. However, in the x = 0.75 sample the better momentum resolution of the x-ray technique (compared to neutrons) shows that the ordering is not truly long range. Both the U and Pu moments have a correlation length of some 400 Å only, even at the lowest temperature. For higher harmonics, especially the third order, the correlation length is even shorter. The observation of a second-order resonance harmonic is linked to the multi-k nature of the configurations, and its unusual temperature dependence is explained by using the phase diagram established for the x = 0.75 sample by neutron diffraction. We conclude with a discussion of the frustration effects that have been observed in the x = 0.75 sample and some suggestions for further work.

Additional information

Authors: NORMILE P S, Department of Physics, Oliver Lodge Laboratory, The University of Liverpool (GB);STIRLING W G, Department of Physics, Oliver Lodge Laboratory, The University of Liverpool (GB);MANNIX D, European Commission, Joint Research Centre, Institute for Transuranium Emements, Karlsruhe (DE);LANDER G H, European Commission, Joint Research Centre, Institute for Transuranium Emements, Karlsruhe (DE);WASTIN F, European Commission, Joint Research Centre, Institute for Transuranium Emements, Karlsruhe (DE);REBIZANT J, European Commission, Joint Research Centre, Institute for Transuranium Emements, Karlsruhe (DE);BOUDAROT F, Départment de Recherche Fondamentale sur la Matière Condensée, Grenoble (FR);BURLET P, Départment de Recherche Fondamentale sur la Matière Condensée, Grenoble (FR);LEBECH B, Department of Physics, Risø National Laboratory, Roskilde (DK);COBURN S, Department of Physics, Brookhaven National Laboratory, Upton, New York (US)
Bibliographic Reference: An article published in: Physical Review B, 66, 014405 (2002)
Availability: This article can be accessed online by subscribers, and can be ordered online by non-subscribers, at: http://link.aps.org/abstract/PRB/v66/e014405
Record Number: 200215696 / Last updated on: 2002-12-23
Category: PUBLICATION
Original language: en
Available languages: en