Neutron scattering studies of nuclear orientation in the μK range

In this paper the application of neutron diffraction to nuclear magnetism is discussed. Experiments have been performed with polarized and unpolarized neutrons on systems with hyperfine-induced, hyperfine-enhanced and magnetic-field-induced nuclear polarization. It is shown that these measurements will yield nuclear temperatures, nuclear spin lattice relaxation times and information about nuclear magnetic order. Nuclear T below 600 μK have been obtained. Experiments planned in the nK range are discussed. (author)