Comparison of resonant inelastic x-ray scattering spectra and dielectric loss functions in copper oxides

Abstract

We report empirical comparisons of Cu K-edge indirect resonant inelastic x-ray scattering (RIXS) spectra, taken at the Brillouin-zone center, with optical dielectric loss functions measured in a number of copper oxides. The RIXS data are obtained for Bi2CuO4 [Bi subscript 2 CuO subscript 4], CuGeO3 [CuGeO subscript 3], Sr2Cu3O4Cl2 [Sr subscript 2 Cu subscript 3 O subscript 4 Dl subscript 2], La2CuO4 [La subscript 2 CuO subscript 4], and Sr2CuO2Cl2 [Sr subscript 2 CuO subscript 2 Cl subscript 2], and analyzed by considering both incident and scattered-photon resonances. An incident-energy-independent response function is then extracted. The dielectric loss functions, measured with spectroscopic ellipsometry, agree well with this RIXS response, especially in Bi2CuO4 [Bi subscript 2 CuO subscript 4] and CuGeO3 [CuGeO subscript 3].