Polarized neutron study of CeSn3 (invited)

Abstract

Over the past several years there has been considerable interest in materials exhibiting a nonintegral valence. As a result the properties of cerium metal and its compounds have been the subject of many theoretical and experimental investigations. In the present experiment polarized neutron scattering techniques have been used to study the spatial distribution and temperature dependence of the magnetization induced in a single crystal of CeSn₃ by a magnetic field of 42.5 kG. In the 40–300 K temperature range the measured magnetic form factor is in good agreement with the 4f magnetic form factor of Ce³⁺. Below 40 K, on the other hand, the magnetic form factor measurements suggest that the induced magnetization contains a large component of 5d electronic character of e_g symmetry, which can account, at least partly, for the increase in the magnetic susceptibility of CeSn₃ at low temperatures. The results will be discussed in terms of a model in which the 4f level is positioned slightly above the Fermi energy and is hybridized with the conduction band. Band theoretical calculations have been performed to determine the nature of the electronic wavefunctions at the Fermi level.