Direct Observation of Phase Coherence in 3-k Magnetic Configurations

Abstract

We report the observation by neutron diffraction of phase coherent Bragg reactions in a multi-k magnetic confguration with a spatial periodicity outside the conventional scattering cross-section. The peaks, which exist in the 3-k state of UAs0:8Se0:2, display long-range order with a wavevector dependence characteristic of a magnetic interaction. The results confirm the long-range order and temperature dependence reported in an earlier study of similar peaks in this material using x-ray resonant scattering by (a) the non-trivial extension to the technique of neutron diffraction, and (b) the observation of similar 3-k phase-coherent re ections in other samples by x-ray resonant scattering. The importance of the neutron diffraction results lies primarily in the fact that magnetic neutron diffraction is well established as a weak probe operating on thermodynamic time scales.