Abstract
The charge distribution in Pb2Sr2YCu3O8+δ and PbBaSrY1-xCaxCu3O7+δ has been studied by X-ray photoelectron spectroscopy (XPS) and X-ray absorption near-edge structure (XANES). The Cu 2p core-level and the Pb M3 XANES show that the valences of Cu and Pb in the blocking layers are + 1 and + 2, respectively, for the oxides synthesized in a reducing atmosphere (δ = 0). The valences of Cu and Pb increase after oxidation by annealing in O2 gas. On the other hand, the substitution of Ca for Y (x = 0.2) hardly changes the valences of Cu and Pb. The core-levels of Ba, Sr and Y are not changed in the binding energy by the oxidation, but are shifted to the lower-binding-energy side by the substitution. These results will be discussed in terms of charge distributions in the crystal structures before and after the oxidation and substitution.
Original language | English |
---|---|
Pages (from-to) | 503-507 |
Number of pages | 5 |
Journal | Journal of Electron Spectroscopy and Related Phenomena |
Volume | 88-91 |
Publication status | Published - 1998 Mar 1 |
Externally published | Yes |
Keywords
- Charge distribution
- Pb-based high-T
- Superconductor
- X-Ray absorption near-edge structure
- X-Ray photoelectron spectroscopy
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Radiation
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Spectroscopy
- Physical and Theoretical Chemistry