The Cu valence in the highT c superconductors and in monovalent, divalent and trivalent copper oxides determined from XPS core level spectroscopy
| Autor: | C. Politis, Stefan Hüfner, P. Steiner, H. P. Müller, B. Siegwart, I. Sander, V. Kinsinger, R. Hoppe |
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| Rok vydání: | 1987 |
| Předmět: |
Superconductivity
Materials science High-temperature superconductivity Valence (chemistry) chemistry.chemical_element Condensed Matter Physics Copper Spectral line Electronic Optical and Magnetic Materials Ion law.invention X-ray photoelectron spectroscopy chemistry law Physical chemistry General Materials Science Spectroscopy |
| Zdroj: | Zeitschrift f�r Physik B Condensed Matter. 67:497-502 |
| ISSN: | 1434-6036 0722-3277 |
| DOI: | 10.1007/bf01304119 |
| Popis: | A number of theoretical models have been developed to explain the unexpected high temperature superconductivity in La-Me-Cu-oxides (Me=Ba, Sr) and Y-Ba-Cu-oxides. Some of these models invoke charge fluctuations on the copper ions in the superconductors between a 2+ and a 3+ state. In order to test these possibilities we have measured the Cu−2p 3/2-core level spectra of NaCuO2 in which the copper ion is in a 3+ state and compared it with the core line position in pure CuO and to superconducting oxides. The data strongly suggest, that there is, if any very little Cu3+ in the superconducting compounds present. However, we notice, that in comparison to trivalent and monovalent copper oxides the Cu−2p 3/2 line in CuO and the superconducting oxides is unexpectedly broad. The cause of this large linewidths remains so far unexplained. |
| Databáze: | OpenAIRE |
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