In the filled skutterudite PrFe4Sb12 with high Pr-site filling fraction synthesized under high pressure, the bulk properties indicate a singlet ground state of the crystal field (CF) and no phase transition at low temperature, in contrast to the reported magnetic ordering in the samples with relatively low filling fraction. In order to clarify the CF states in PrFe4Sb12 microscopically, we have performed the inelastic neutron scattering experiment on the PrFe4Sb12 synthesized under high pressure. The CF level scheme obtained from the results is Γ1 (0 meV) - Γ(2)4 (2.3 meV) - Γ(1)4 (11.4 meV) - Γ23 (18 meV). Furthermore, it is found that the singlet-triplet states in low energy region have large off-diagonal matrix elements of quadrupoles, indicating the similarity of the CF states in the heavy fermion superconductor PrOs 4Sb12.
ASJC Scopus subject areas
- Physics and Astronomy(all)