Unusual magnetism in new kagome material UVSn.

Materials in the family VSn ( = rare earth) provide a unique platform to investigate the interplay between local moments from layers and nonmagnetic vanadium kagome layers. Yet, the investigation of actinide members remains scarce. Here we report the synthesis of UVSn single crystals through the self-flux technique. Physical property measurements reveal two uranium-driven antiferromagnetic transitions at  = 29 K and  = 24 K, a complex field-temperature phase diagram, and unusual negative domain-wall magnetoresistance. Specific heat and angle-resolved photoemission spectroscopy measurements show a moderate -electron enhancement to the density of states at the Fermi level ( ), whereas our band structure calculations place the vanadium flat bands 0.25 eV above . These findings point to a materials opportunity to expand the uranium 166 family with the goal of enhancing correlations by tuning 5 and 3 flat bands to .