A series of samples, Y1-xCaxBa2-xLaxCu3Oy (x = 0 ∼ 0.6), were prepared and studied by X-ray absorption near-edge spectroscopy (XANES). The oxygen content y in these samples remained about the same for all x. Both the O-1s and Cu-2p3/2 XANES results indicate that the total number of holes remained essentially unchanged. The O-1s XANES gives no sign showing that there are La ions on the Y sites. Our data indicated that the Ca2+ and La3+ doping changed not only the lattice symmetry but also the electronic structure at the Fermi energy in the valence band. The results derived from the O-1s XANES showed that the holes on the CuO2 planes decreased, while the holes on the O(1) and O(5) sites en the basal plane increased, as the doping concentration x increased.
|Number of pages||11|
|Journal||Chinese Journal of Physics|
|Publication status||Published - 2003 Feb 1|
ASJC Scopus subject areas
- Physics and Astronomy(all)