Unravelling the role of Cu-O chain length on the superconducting properties of via Al doping and clusteringM. Scavini1, M. Daldosso1, 2, S. Cappelli1, C. Oliva1, M. Brunelli2, C. Ferrero2 and A. Lascialfari3, 4
1 Dipartimento di Chimica Fisica ed Elettrochimica dell'Universita di Milano I-20133 Milano, Italy
2 European Synchrotron Radiation Facility - av. J. Horowitz, BP 220 F-38043 Grenoble Cedex, France
3 Istituto di Fisiologia Generale e Chimica Biologica, Università di Milano Milano, Italy
4 CNR-INFM, c/o Dipartimento di Fisica "A. Volta", Università di Pavia I-27100 Pavia, Italy
received 19 May 2006; accepted in final form 18 September 2006
published online 11 October 2006
The superconducting properties of the superconductor change dramatically upon oxidation. The driving force for these changes is still under debate because many concomitant structural changes occur. In order to highlight the specific role of Cu-O chain ordering on the rise of superconductivity in this system, Al-doped samples have been examined, having equal aluminium and oxygen concentration and nearly the same structure but different mean length of Cu-O chain fragments. For the first time, it is clearly shown that, keeping all the other structural properties unchanged, the local increase of the chain length determines a significant enhancement of the superconducting properties, i.e. TC and Meissner fraction.
61.10.Nz - X-ray diffraction.
74.62.Dh - Effect of crystal defects, doping and substitution.
74.72.Bk - Y-based cuprates.
© EDP Sciences 2006