Magnetic properties of UP₂ probed by high-magnetic field

Due to its complex tetragonal crystal structure, with three distinct uranium sites, UP₂ stands out among other uranium dipnictides such as UAs₂, USb₂, and UBi₂. At ambient pressure, UP₂ exhibits antiferromagnetic ordering with T_N = 204 K and an effective moment of μ_eff = 2.29 μ_B/U. The neutron scattering experiment indicates that the ordered moment is parallel to the [0 0 1] direction and equals 2.0 μ_B/U. There is, however, a lack of information regarding the magnetic properties of UP₂ in high magnetic fields, particularly concerning its magnetic phase diagram. Here we present detailed experimental and theoretical studies of magnetic properties of oriented high-quality single crystals of UP₂. The measurements were performed at the High Magnetic Field Laboratory, Los Alamos National Laboratory, using pulsed magnetic fields up to 60 T. We will discuss details of the obtained phase diagram and its relationships to the localization/delocalization of 5f-electrons in this material.