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Updated: Jul 17, 2026

Dissolution Dynamic Nuclear Polarization Instrumentation for Real-time Enzymatic Reaction Rate Measurements by NMR
Published on: February 23, 2016
NMR evidence for higher-order multipole order parameters in NpO2
1ASRC, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan.
Abstract:
We report a microscopic investigation of multipolar order parameters in the ordered state of NpO2 conducted via 17O NMR on a single crystal. From the angular dependence of hyperfine fields at 17O nuclei, we have obtained clear evidence for the appearance of field-induced antiferro-octupolar as well as field-induced antiferro-dipolar moments below T0 = 26 K. We have also observed oscillatory spin-echo decay, which is well understood in terms of small electric field gradients created by antiferro-quadrupolar ordering. This reveals that the quadrupolar order parameter is directly observable by means of NMR. The present NMR studies provide definitive support for a proposed longitudinal triple-q type octupolar-quadrupolar ordering model for NpO2.
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