Polarized Oxygen Kα and Copper Lα X-Ray Emission Spectroscopy of YBa2Cu3O7

Abstract

Abstract The high temperature superconductor YBa2Cu3O7 is characterized by a very anisotropic structure. The electronic structure of this compound is studied using high resolution valence band spectroscopy within an electron probe microanalyzer. From single crystals and melt-textured specimens,orientation dependent Cu-Lα spectra are obtained using a beryl crystal. The Cu-Lα spectra with polarization parallel to the z-direction show a larger energetic breadth compared to those obtained with polarization perpendicular to z. This is caused by occupied Cu3d3z 2-r 2 like states, as could be shown by other workers using cluster calculations. With a chlinochlore crystal, the polarized O-Kα, spectra can be used to investigate the orientation of single crystal areas. The spectra map the bandlike O2p states. In contrast to the Cu-Lα spectra,the partial O -Kα spectra agree with band structure calculations in the local density approximation done by other workers.