Magnetization density distribution in U2Co2Sn

A magnetization density study by means of polarized-neutron scattering on the intermetallic compound UzCo2Sn is reported. U2Co2Sn belongs to the large An(2)T(2)X (An = U, Np, Pu, Am; T = transition metal; X = In, Sn) family of compounds crystallizing in an ordered variant of the tetragonal U3Si2 type of structure (space group P4/mbm). U2Co2Sn does not order magnetically but has a large magnetic susceptibility that qualifies it as an enhanced paramagnet or spin fluctuator. We report single-crystal magnetization measurements that show a significant magnetic anisotropy, with a c-axis susceptibility exceeding that measured on the basal plane by a factor of four. The magnetization density distribution in the unit cell was measured at 2 K by polarized-neutron scattering under a magnetic field of 5.5 T applied parallel to the c-axis. It was found that the major contribution to the magnetic susceptibility is located on the U atoms (mu(U) = 118(3) m mu(B)) but a small response from the Co atoms is also measured (mu(Co) = 13(2) m mu(B)).