NEUTRON POWDER-DIFFRACTION STUDIES OF U2NI2IN AND U2PD2IN

We have performed neutron diffraction experiments on U2Ni2In and U2Pd3 In. Bath compounds crystallize with a tetragonal structure, U3Si2-type , space group P4/mbm; and are non-collinear antiferromagnets at low te mperatures (U2Ni2In, T-N=15 K; U2Pd2In, T-N less than or equal to 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 a re perpendicular to the tetragonal c-axis, but their relative arrangem ent 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) mu(B) in U2Ni2I n and M(U)=1.55(5) mu(B) in U2Pd2In.