Crystal electric fields in rare earth-Ba-Cu-oxide superconductors

Abstract The crystalline electric field (CEF) in HoBa 2 Cu 3 O 7 −y with y ≈ 0 and 1 has been measured using inelastic neutron scattering. The CEF potential at the rare earth (RE) site is found to be quite sensitive to the oxygen stoichiometry reflecting changes in local symmetry (orthorhombic for y ≈ 0 and tetragonal y ≈ 1) with little evidence of significant charge redistribution in the vicinity of the RE site.