Abstrakt
We report on the crystal and magnetic structures, magnetic, transport, and thermal properties of U2Rh2Sn single crystals studied in part in high magnetic fields up to 58 T. The material adopts a U3Si2-related tetragonal crystal structure and orders antiferromagnetically below T-N = 25 K.
The antiferromagnetic structure is characterized by a propagation vector k = (001/2). The magnetism in U2Rh2Sn is found to be associated mainly with 5f states.
However, both unpolarized and polarized neutron experiments reveal at low temperatures in zero field non-negligible magnetic moments also on Rh sites. U moments of 0.50(2) mu(B) are directed along the tetragonal axis while Rh moments of 0.06(4) mu(B) form a noncollinear arrangement confined to the basal plane.
The response to applied magnetic field is highly anisotropic. Above similar to 15 K the easy magnetization direction is along the tetragonal axis.
At lower temperatures, however, a stronger response is found perpendicular to the c axis. While for the a axis no magnetic phase transition is observed up to 58 T, for the field applied at 1.8 K along the tetragonal axis we observe above 22.5 T a field-polarized state.
A magnetic phase diagram for the field applied along the c axis is presented.