Evidence for nuclear-spin order in double-hcp praseodymium by neutron diffraction

In search of evidence for nuclear-spin order in double--hexagonal-close-packed Pr metal, neutron-diffraction experiments have been done at millikelvin temperatures. The results of polarization analysis of two magnetic satellites on the [100] reciprocal-lattice axis, and the temperature dependence of the intensities of these satellites have been interpreted in terms of a model which has substantial nuclear-spin order on both hexagonal- and cubic-site atoms.