Abstract :
The crystal and magnetic structures of UCu5In have been investigated by means of neutron powder diffraction measurements. This compound crystallizes with the orthorhombic CeCu5Au-type structure (space group Pnma). Below 25(1) K, UCu5In exhibits a non-collinear antiferromagnetic structure of uranium magnetic moments, which are confined to the ac plane. At 1.4 K the ordered moment amounts to 1.55(2)μB and is tilted from the c-axis by an angle of 58.2(5)°. This angle is slightly temperature-dependent and increases with rising temperature. This rather complex magnetic structure of UCu5In probably results from the interplay of anisotropic magnetic exchange interactions and a strong crystal electric field effect.
