title: X-ray crystal structures of Al-doped (Y,Ca)Ba2Cu3O(7-y) whiskers.
abstract: Al(+3)-doped (Y,Ca)Ba2Cu3O(7-y) (YBCO) whiskers have been synthesized using a solid-state reaction technique. These materials are promising candidates for solid-state THz applications based on sequences of Josephson Junctions (IJJs). Alumina addition was systematically varied and the effect of aluminium incorporation on the structure has been investigated using single-crystal X-ray diffraction. Aluminium only replaces Cu atoms in the O-Cu-O-Cu chains and a gradual transition from orthorhombic to tetragonal space group occurs, thus increasing the Al content. A gradual modification of the coordination sphere of the copper site has also been observed. The Ca(2+) ion substitutes mainly the Y(3+) ion and also, to a small extent, the Ba(2+) ion.
authors.affiliation: Department of Chemistry and Centro Interdipartimentale di Cristallografia Diffrattometrica (CrisDi), University of Turin, Via P. Giuria 7, 10125 Turin, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Bertolotti
authors.affiliation: Department of Chemistry and Centro Interdipartimentale di Cristallografia Diffrattometrica (CrisDi), University of Turin, Via P. Giuria 7, 10125 Turin, Italy.
authors.forename: Leandro
authors.initials: L
authors.lastname: Calore
authors.affiliation: Department of Chemistry and Centro Interdipartimentale di Cristallografia Diffrattometrica (CrisDi), University of Turin, Via P. Giuria 7, 10125 Turin, Italy.
authors.forename: Giuliana
authors.initials: G
authors.lastname: Gervasio
authors.affiliation: Department of Chemistry and Centro Interdipartimentale di Cristallografia Diffrattometrica (CrisDi), University of Turin, Via P. Giuria 7, 10125 Turin, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Agostino
authors.affiliation: NIS Centre of Excellence, Via P. Giuria 7, 10125 Turin, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Truccato
authors.affiliation: Department of Chemistry and Centro Interdipartimentale di Cristallografia Diffrattometrica (CrisDi), University of Turin, Via P. Giuria 7, 10125 Turin, Italy.
authors.forename: Lorenza
authors.initials: L
authors.lastname: Operti
keywords: Al-doping; high-temperature superconductors; intrinsic Josephson junctions; whiskers