PULSED-NEUTRON LAUE DIFFRACTION STUDIES OF THE MAGNETIC-STRUCTURES OFHOLMIUM AND TERBIUM

We report elastic magnetic neutron diffraction measurements on the rar e earth metals holmium and terbium, using the white-beam SXD diffracto meter at the ISIS pulsed neutron source (Rutherford Appleton Laborator y). Holmium, which has been studied extensively in previous neutron an d X-ray investigations, was employed in exploratory measurements to ex amine the viability of the instrument. In addition, the extended Q ran ge of SXD was used to compare theoretical and experimental results for the magnetic form factor of holmium beyond the range of former triple -axis experiments. Subsequent measurements on terbium were then carrie d out, including a re-determination of the sub-lattice magnetisation e xponent beta.