INTERMULTIPLET TRANSITIONS IN OPTICALLY OPAQUE EUBA2CU3O7 - AN INELASTIC NEUTRON-SCATTERING STUDY

We report the results of inelastic neutron scattering (INS) studies of the J=0 to J=1 magnetic transitions in EuBa2Cu3O7. The low J values of these multiplets restrict our crystal field analysis to the second-order crystalline electric field (CEF) parameters obtained by fitting the splitting of the J=1 multiplet, and the spin-orbit coupling parameter, which is used to fit the energy of the J=0 to J=1 multiplet splitting. We compare our results with those derived from other INS studies on different rare earths, as well as with and derived from Mossbauer studies. The J=0 to J=1 splitting observed here is smaller than previously seen by optical spectroscopic studies on a variety of transparent, ionic compounds, necessitating the inclusion of a free-ion parameter in the fitting procedure. This work represents the first time that a complete excited multiplet has been seen for R in RBa(2)Cu(3)O(7). These results are particularly germane to crystal field analyses of the light rare earth ions in optically opaque materials, where assumptions about free-ion parameters are essential for a meaningful analysis.