Superconductivity suppression of R(Ba1-zRz)(2)Cu3O7+delta (R = Nd, Pr) probed by soft-x-ray absorption spectroscopy
Journal
Physical Review B
Journal Volume
59
Journal Issue
5
Pages
3855-3861
Date Issued
1999
Author(s)
Abstract
O K-edge x-ray-absorption near-edge-structure (XANES) spectra of (Formula presented) for (Formula presented) and (Formula presented) for (Formula presented) were performed to search for microstructural features and hole distribution related to the superconducting properties. Near the O (Formula presented) edge, prepeaks at ∼527.6 and ∼528.3 eV are assigned to transitions into O (Formula presented) holes located in the (Formula presented) ribbons and (Formula presented) planes, respectively. As deduced from O (Formula presented) absorption spectra of (Formula presented) for (Formula presented) the hole concentrations in the (Formula presented) planes and (Formula presented) ribbons decrease monotonically with increasing Pr doping. The present XANES results clearly reveal that the suppression of superconductivity with Pr doping in (Formula presented) results predominantly from the hole depletion effect. The effect of Pr on the Ba site in (Formula presented) is to reduce the hole concentration in the (Formula presented) planes and to create localized fivefold Cu chain sites. (Formula presented) of (Formula presented) is depressed upon Pr doping, primarily due to hole filling and hole localization. Compared to (Formula presented) the enhanced suppression of (Formula presented) in (Formula presented) is primarily due to the hole localization. © 1999 The American Physical Society.
Type
journal article