Neutron scattering experiment on U₃Pd₂₀Si₆ I: Crystal and magnetic structures

Neutron elastic scattering experiments were carried out in order to reveal the crystal and magnetic structures of U₃Pd₂₀Si₆. The crystal structure is found to be a Cr₂₃C₃-type cubic structure which is the same as the rare earth R₃Pd₂₀X₆(R = rare earth, X = Si, Ge) compounds. U₃Pd₂₀Si₆ shows two magnetic transitions at 19 and 2K. Below 19K, the uranium moment of the 8c sites antiferromagnetically ordered with the propagating vector k = [1 1 1] and the ordered magnetic moment was estimated to be about 1.73μ_B/U.