Structure and superconductivity of YSr2Cu3O7-d

Almost pure samples of YSr2Cu3O7-d have been synthesized under 3GPa and in the presence of KClO3. The structure and oxygen stoichiometry were determined by refining the powder neutron diffraction data. The as-prepared sample was found to be tetragonal (P4/mmm space group, a = 3.7855(4), c = 11.386(2) Angstrom), with d = 0.2. The T-c onset measured by both resistivity and susceptibility, was found to be reproducible at approximate to 63K. When comparing these data with the corresponding ones of the Y(Ba1-xSrx)(2)Cu3O7-d Solid solution with similar oxygen stoichiometry, the lattice parameters and most of the interatomic distances seem to scale monotonically with x, while T-c and the Cu1O1 distance seem to go through a minimum at x = 0.5.