Observations of Cef-Split Intermultiplet Transitions in Optically Opaque EuBa2Cu3O7 Using Inelastic Neutron Scattering

Abstract

ABSTRACTInelastic neutron scattering (INS) results on the intermultiplet transitions J=0 → 1 and J=1 → 2 in optically opaque EuBa2Cu3O7 are reported. Whereas these multiplets are split by the crystalline electric field (CEF), their low J values are influenced to first order only by the second-order (J=1) and additional fourth-order (J=2) CEF parameters. and the spinorbit coupling parameter were obtained by fitting the splitting of the J=l multiplet and the energy separation between the J=0 and 1 multiplets. The J=0 → 1 splitting observed here is smaller than previously seen by optical spectroscopic studies on a variety of transparent, ionic compounds, necessitating fitting of the free-ion parameter. Additional spectroscopic information on the J=2 multiplet indicates that additional fitting of free ion parameters must be included to adequately model the observed low energy separation between the two lowest J-multiplets. Preliminary calculation on the Q-dependence of the CEF split J=0 → 1 transitions and the comparison with observations are presented.