CRYSTAL-FIELD SPLITTINGS AND MAGNETIC-PROPERTIES OF PR3+ AND ND3+ IN RBA2CU3O7

Neutron inelastic scattering spectra are reported for superconducting NdBa2Cu3O7 and insulating PrBa2Cu3O7. These spectra are analyzed in terms of standard crystal-field theory for 3+ rare-earth ions in a manner that is consistent with the level assignments made in a similar study of HoBa2Cu3O7. Using the eigenfunctions and eigenvalues obtained from this analysis of the inelastic neutron scattering spectra, the corresponding magnetic susceptibilities as a function of temperature were calculated according to the van Vleck formalism. Good agreement with experimental susceptibilities is achieved for all three compounds over the range of 100 to 300 K. The observed magnetic scattering in NdBa2Cu3O7 agrees very well with the crystal-field calculations. In spite of the observed large intrinsic widths of the experimental crystal-field peaks for PrBa2Cu3O7, the measured intensity is consistent with the calculated crystal-field excitation spectrum for Pr3+ ions in this lattice. The standard crystal-field treatment of Pr3+ ions is shown to explain the magnetic properties of PrBa2Cu3O7 with no need to consider either the static or dynamic coexistence of Pr3+ and Pr4+.