Anisotropic physical properties of single-crystal U2Rh2Sn in high magnetic fields

Abstract

We report on the crystal and magnetic structures, magnetic, transport, and thermal properties of ${\mathrm{U}}_{2}{\mathrm{Rh}}_{2}\mathrm{Sn}$ single crystals studied in part in high magnetic fields up to 58 T. The material adopts a ${\mathrm{U}}_{3}{\mathrm{Si}}_{2}$-related tetragonal crystal structure and orders antiferromagnetically below ${T}_{N}=25$ K. The antiferromagnetic structure is characterized by a propagation vector $\mathit{k}=(00\frac{1}{2})$. The magnetism in ${\mathrm{U}}_{2}{\mathrm{Rh}}_{2}\mathrm{Sn}$ 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) ${\ensuremath{\mu}}_{B}$ are directed along the tetragonal axis while Rh moments of 0.06(4) ${\ensuremath{\mu}}_{B}$ form a noncollinear arrangement confined to the basal plane. The response to applied magnetic field is highly anisotropic. Above $\ensuremath{\sim}15\phantom{\rule{0.28em}{0ex}}\mathrm{K}$ 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.