Determination of atomic site susceptibility tensors from neutron diffraction data on polycrystalline samples

Polarized neutron diffraction can provide information about the atomic site susceptibility tensor Xij characterizing the magnetic response of individual atoms to an external magnetic field (Gukasov and Brown 2002 J. Phys.: Condens. Mater. 14 8831). The six independent atomic susceptibility parameters (ASPs) can be determined from polarized neutron flipping ratio measurements on single crystals and visualized as magnetic ellipsoids which are analogous to the thermal ellipsoids obtained from atomic displacement parameters (ADPs). We demonstrate now that the information about local magnetic susceptibility at different magnetic sites in a crystal can also be obtained from polarized and unpolarized neutron diffraction measurements on magnetized powder samples. The validity of the method is illustrated by the results of such measurements on a polycrystalline sample of Tb(2)Sn(2)O(7).