Electronic Transitions of Holmium in Pb sub 2 Sr sub 2 HoCu sub 3 O sub 8 Observed by Inelastic Neutron Scattering

The electronic behavior of the exp 5 I sub 8 Russell Saunders ground multiplet of Ho exp 3+ in Pb sub 2 Sr sub 2 HoCu sub 3 O sub 8 has been investigated using inelastic neutron scattering. Ten peaks in the excitation spectra that are associated with crystal field transitions are observed. The peaks are only slightly broader than expected from instrument resolution, indicating that there are no strong interactions between the local holmium f states and the CuO conduction states. Comparing the energies and intensities of the experimental peaks with those expected from modeling convinces us that there are at least three states populated at the temperature of our experiment (15K), making the assignments of transitions very difficult in the absence of further data.