Intermultiplet transitions in optically opaque EuBa 2Cu 3O 7: an inelastic neutron scattering study

Abstract

We report the results of inelastic neutron scattering (INS) studies of the J = 0 to J = 1 magnetic transitions in EuBa 2Cu 3O 7. 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 Mössbauer 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 2Cu 3O 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.