- Authors:
- DOI:
- 10.1103/physrevb.66.014405
- 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 (U1-xPux)Sb solid solution. Neutron diffraction has established the ordering wave vector (k=1 for x=0.25 and 0.50, as in x=0, USb, and k=0.25 for x=0.75), 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. Experiments with a field applied to the sample have shown that the x=0.25 and 0.50 samples are triple k (as in x=0, USb), but that the x=0.75 sample is initially (at T-N) triple k, but at a lower temperature of T' starts to transform to a single-k configuration (as found in x=1, PuSb). The (H, T) phase diagram of this sample is presented. At T=10 K some 30% of the x=0.75 sample remains in the (high-temperature) 3k state. 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 Angstrom 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.
- Type:
- Journal article
- Language:
- English
- Published in:
- Physical Review B Condensed Matter, 2002, Vol 66, Issue 1
- Keywords:
- 5-I nano
- Main Research Area:
- Science/technology
- Publication Status:
- Published
- Review type:
- Peer Review
- Submission year:
- 2002
- Scientific Level:
- Scientific
- ID:
- 161155401
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