Origin of superconductivity suppression in (Dy1-xPrx)Ba2Cu3O7 studied by soft-x-ray absorption spectroscopy

O K-edge and Cu L23-edge x-ray-absorption near-edge structure (XANES) spectra for the series of (Dy1-xPrx)Ba2Cu3O7-δ compounds (x=0 endash 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 CuO3 ribbons and CuO2 planes, respectively. Both the O 2p hole concentration in the CuO2 planes and CuO3 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 Cu3d9L defected states show a linear decrease in spectral weight as the Pr doping increases, where L denotes the ligand O 2p hole on the CuO3 ribbons and the CuO2 planes. copyright 1997 The American Physical Society