Changes in the Cu K-edge XANES of Bi 2201 phase by N2 annealing
| Autor: | Yasuhiro Murakoshi, Maki Kawai, Shiro Kambe, Rika Sekine |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Materials science
Condensed matter physics Annealing (metallurgy) Octahedral symmetry Energy Engineering and Power Technology chemistry.chemical_element Electronic structure Condensed Matter Physics Oxygen XANES Electronic Optical and Magnetic Materials K-edge chemistry Electrical and Electronic Engineering Energy structure Single crystal |
| Zdroj: | Physica C: Superconductivity. :923-924 |
| ISSN: | 0921-4534 |
| DOI: | 10.1016/0921-4534(91)91685-w |
| Popis: | Tc of the Bi 2201 system is known to increase by annealing in the absence of oxygen. In order to understand the changes of the geometric or electronic structure in CuO 2 plane, the energy structure of Bi system is studied by Cu K-edge XANES. For the single crystal of Bi 2212, where the CuO 2 layer has pyramidal structure, 1s-4p π transition splits into two peaks. This splitting is neither observed for the single crystal of Bi 2201 phase nor for the Nd- or the La- systems. When the Bi 2201 phase is annealed in the absence of oxygen, the splitting in the 1s-4p π transition is also observed. This may be due to the fact that the apex oxygen in 2201 phase moves into the direction from CuO 2 plane to BiO plane, and as a result, the octahedral symmetry breaks, giving similar energy structure to pyramidal CuO 2 plane. |
| Databáze: | OpenAIRE |
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