NEUTRON-DIFFRACTION AND ULTRASONIC STUDIES OF SPIN-SLIP STRUCTURES INHOLMIUM

Spin-slip behaviour in high-purity holmium single crystals is characte rized by neutron diffraction and ultrasonic velocity and attenuation m easurements as a function of temperature and of magnetic field applied along b, c, and a axes. Neutron diffraction measurements of intensity and turn angle give information on wave vector lock-in effects for va rious spin-slip structures in applied fields. These findings are suppl emented with ultrasonic studies of the elastic constants C-33 and C-44 and corresponding attenuation coefficients alpha(33) and alpha(44). V arious phase diagrams are presented and results compared with experime nts by other groups and with some theoretical predictions.