Abstract
Bulk-sensitive, polarization-dependent oxygen K- and copper L-edge absorption spectra of single-domain with planes tilted off the sample surface were measured. A novel experimental configuration was utilized to achieve complete polarization geometry and eliminate optical path variations. Contrary to previous measurements, our data show for both intrinsic and doped holes a significant amount of O2 character, likely associated with apical O, but a very weak Cu3- character. The quantitative results impose strong contraints on superconductivity models invoking out-of-plane orbitals, and suggest that the apical O 2 orbital may play an important role in high- phenomena.
- Received 18 February 1992
DOI:https://doi.org/10.1103/PhysRevLett.68.2543
©1992 American Physical Society