Magnetic form factor of URu2Si2

We report the field-induced magnetic form factor of the heavy-electron system URu2Si2 obtained by using polarized neutrons. The neutron experiments were performed on the two single crystals at 60 K by applying a magnetic field of 6 T along the tetragonal c-axis. The observed magnetic form factor is close to the theoretical 5f form factor of the free U3+ or U4+ ions calculated by the dipole approximation as other U-based intermetallic superconductors. However, the extrapolated value at sin theta/lambda = 0 (0.07 mu(B)/U) is smaller than the bulk magnetization value (0.10 mu(B)/N). Therefore, this result indicates some contribution other than 5f electrons to the bulk magnetization of URu2Si2. (c) 2006 Elsevier B.V. All rights reserved.