Compositional dependence of properties of Bi2−yPbySr3−xCaxCu2O8+z films grown by liquid phase epitaxy

Abstract
The growth of Bi2−yPbySr3−xCaxCu2O8+z films by liquid phase epitaxy is illustrated. Films are shown to be good single crystals epitaxial relative to the substrate. Films stoichiometry was varied changing the melt composition. The effects of the Ca and Pb stoichiometry on both the structural and superconducting properties are discussed. The c lattice parameter of the films was found to increase linearly with the Ca content per formula unit with a slope of 0.3 A each 0.5 Ca atoms per formula unit. No sizeable changes in the superconducting properties were found for films with a Ca content between 0.8 and 1.3 atoms per formula unit. Lead doping is shown to decrease the transition temperature without broadening the transition itself. 0.4 lead atoms per formula unit decreased the transition temperature down to 69 K.