Polarized neutron studies of CeNiSn

To achieve a deeper understanding of the hybridization process in the so-called 'low-charge-carrier Kondo system', the magnetization density within the unit cell, induced by an external magnetic field, has been investigated by means of polarized neutron diffraction for single crystals of CeNiSn. As expected, most of the induced moment is associated with the Ce 4f electrons at the Ce site, but a significant magnetization density has also been observed at the Ni site. This observation is evidence that the Ni 3d band is not filled, and confirms recent band-structure calculations that suggest the Ce 4f - Ni 3d hybridization to be fundamental to the production of a 'gap' at the Fermi level in CeNiSn. We suggest that this hybridization process is the cause of the anisotropy of the physical properties of this material. (author)