| Numéro |
J. Phys. IV France
Volume 7, Numéro C2, Avril 1997
Proceedings of the 9th International Conference on X-Ray Absorption Fine Structure
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|---|---|---|
| Page(s) | C2-523 - C2-524 | |
| DOI | https://doi.org/10.1051/jp4/1997081 | |
Proceedings of the 9th International Conference on X-Ray Absorption Fine Structure
J. Phys. IV France 7 (1997) C2-523-C2-524
DOI: 10.1051/jp4/1997081
1 Synchrotron Radiation Research Center (SRRC), Hsinchu, Taiwan, China
2 Department of Chemistry, National Taiwan University, Taipei, Taiwan, China
3 IRC in Superconductivity, University of Cambridge, UK
© EDP Sciences 1997
J. Phys. IV France 7 (1997) C2-523-C2-524
DOI: 10.1051/jp4/1997081
Electronic Structure of (Tl0.5Pb0.5)Sr2(Ca1-xYx)Cu2O7 (x = 0 - 0.9) at 50 K Probed by X-Ray Absorption Spectroscopy
J.M. Chen1, R.S. Liu2 and W.Y. Liang31 Synchrotron Radiation Research Center (SRRC), Hsinchu, Taiwan, China
2 Department of Chemistry, National Taiwan University, Taipei, Taiwan, China
3 IRC in Superconductivity, University of Cambridge, UK
Abstract
High-resolution O K-edge X-ray-absorption near-edge-structure (XANES) spectra for the
series of (Tl0.5Pb0.5)Sr2(Ca1-xYx)Cu2O7 compounds (x = 0 - 0.9) at 50 K were measured using a bulksensitive
X-ray-fluorescence-yield technique. A well-pronounced pre-edge peak at ~ 528.3 eV is
ascribed to the excitations of O Is electrons to O 2p holes located in the Cu02 planes. The intensity of
this pre-edge peak increases with the Ca doping for 0 ≤ x ≤ 0.5. This indicates that the effect of
chemical substitution of Ca2+ for Y3+ is to induce hole states in the Cu02 planes near the Fermi level.
The generation of O 2p holes in the Cu02 planes is probably responsible for inducing a transition from
a semiconductor to a superconductor.
© EDP Sciences 1997