Neutron-scattering study of the nuclear and magnetic structure of DyD3 andassociated vibrational and magnetic excitations

Neutron-diffraction and inelastic-scattering measurements of the hexagonal rare-earth trideuteride DyD3 were undertaken between 1.27 and 295 K. Rietve ld-refined, P (3) over bar c 1-symmetric models of the diffraction data as well as the observed neutron vibrational spectra indicate that DyD3 is crys tallographically isostructural with YD3 and HoD3 over the temperature range measured. Below T-N=3.33(4) K, the Dy sublattice becomes antiferromagnetic ally ordered, with the 5.25(4)mu(B) moment along the c direction. In additi on, the first crystal-field excitation for the J= 15/2 Dy ion has been iden tified at 7.79(8) meV. [S0163-1829(99)02318-8].