Synthesis, characterization and superconducting properties of Pb2Sr2(Y/Ca)Cu3O9−δ single crystals

Single crystals of Pb2Sr2(Y/Ca)Cu3O9-δ have been grown from a PbO-NaCl flux. The absence of CuO flux enables the crystals to be separated non-destructively from the melt using an organic solvent. This method yields high quality, untwinned, reasonably sized crystals with a sharp transition temperature of 84 K. The crystals exhibit an orthorhombic structure with lattice parameters; deduced from a Guinier camera analysis, a = 5.383 (1) Å, b = 5.423 (1) Å and c = 15.765 (2) Å. The crystals are considerably thicker along the c-direction than typical crystals of YBa2Cu3O7-δ and Bi2Sr2CaCu2O8 which facilitates measurements of anisotropic properties. As an example we present a measurement of the component of the resistivity in the ab-plane, and along the c-axis.