Abstract
O K-edge and Cu -edge x-ray-absorption near-edge structure (XANES) spectra for the series of () compounds (x=0–0.7) were measured to investigate how the variation of hole states related to the superconductivity. Near the O 1s edge, prepeaks at ∼527.6 and ∼528.4 eV are assigned to transitions into O 2p holes located in the ribbons and planes, respectively. Both the O 2p hole concentration in the planes and ribbons decrease monotonically with increasing Pr doping, giving evidence in support of the hole depletion model proposed by Liechtenstein and Mazin. It clearly demonstrates that the suppression of superconductivity with Pr-doping results predominantly from the hole depletion effect. In the Cu 2p absorption edge, the high-energy shoulders originating from Cu L defected states show a linear decrease in spectral weight as the Pr doping increases, where L denotes the ligand O 2p hole on the ribbons and the planes.
DOI:https://doi.org/10.1103/PhysRevB.55.14586
©1997 American Physical Society