Resistivity anisotropy in lead-substituted Bi2Sr2CaCu2O8+y

Abstract We show that lead-substitution in single crystals of Bi 2 Sr 2 CaCu 2 O 8+y induces a decrease of both the structural and resistivity anisotropies. In the first place we have found that lead substitution can reduce the resistivity anisotropy ρ c ρ ab by two orders of magnitude and that ρ c changes its behaviour from a semiconductor-like to metallic-like. In the second place, the existence of a threshold value in the amount of lead-substitution, above which iodine intercalation is no longer possible is consistent with the occurence of a strengthening of the binding force between adjacent Bi-O planes.