| Autor: |
Liang, G., Yi, Y., Jardim, R. F., Wang, L. V. |
| Předmět: |
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| Zdroj: |
International Journal of Modern Physics B: Condensed Matter Physics; Statistical Physics; Applied Physics; 12/20/99, Vol. 13 Issue 29/31, p3750, 5p |
| Abstrakt: |
To further study the charge carrier concentration in electron doped cuprate superconductors, a systematic x-ray absorption near edge structure (XANES) measurement has been carried out on Th-doped superconductor system R[sub 2 - χ]Th[sub χ]CuO[sub 4 - & δ] (R = Nd, Sin, and Gd). The XANES results show that, similar to the Ce-doped compounds, while the intensity of the Cu[sup 1+] 4p[sub π] feature increase with the increase of the Th doping level χ, the intensities of the Cu[sup 2+] 4p[sub π] and 4p[sub σ] features decreases. This clearly indicates that the electrons doped by the Th atoms are injected into the local Cu 3d-orbitals. The normalized Cu[sup 1+] 4p[sub π] intensity data show that the Cu[sup 1+] concentration in the Th-doped compound series with different R-elements is linearly proportional to the Th doping-level χ. The data suggest that both Ce and Th donate the same fraction of electrons into the Cu sites. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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