Investigation of the different nature of magnetic hyperfine fields of Ce probes in Gd and matrices

Abstract

The magnetic hyperfine fields (MHF) acting on 140Ce probes diluted in Gd and Co matrices, measured at low temperatures, were compared with those obtained from first-principles electronic structure calculations. It was found that the origin of the MHF for these two situations is completely different even though the total MHF presents similar values on both the cases. For Ce diluted in Gd, the Ce 4f shell is localized and the orbital MHF dominates. On the other hand, for Ce probes in Co matrix the Ce 4f shell is delocalized and, as a consequence, the MHF is dominated by the Fermi-contact contribution.