Neutron powder-diffraction studies of U 2Ni 2In and U 2Pd 2In

Abstract

We have performed neutron diffraction experiments on U 2Ni 2In and U 2Pd 2In. Both compounds crystallize with a tetragonal structure, U 3Si 2-type, space group P4/mbm, and are non-collinear antiferromagnets at low temperatures (U 2Ni 2In, T N = 15 K; U 2Pd 2In, T N ≤ 31 K). Their magnetic structures are respectively described by propagation vectors k = (0, 0, 1 2 ) and k = (0, 0, 0) . The uranium magnetic moments are perpendicular to the tetragonal c-axis, but their relative arrangement within the (001) plane is different for Ni and Pd compounds. At 1.5 K, the uranium magnetic moment value is M U = 0.85(5) μ B in U 2Ni 2In and M U = 1.55(5) μ Bin U 2Pd 2In.