The effect of reaction conditions on the Bi1.6Pb0.4Sr2−xPrxCuO6+δ system

Abstract The final properties of Pb- and Pr-substituted 2201 superconductors depend on processing parameters such as annealing temperature, reaction time, atmosphere and cooling schedule. As the Pr-content is reduced, their effects become more important and less reproducible. For samples having the composition Bi 1.6 Pb 0.4 Sr 1.65 Pr 0.35 CuO 6+δ the T 2 c varies from less than 10 K up to 30 K. We have found that during the final annealing at high temperstures there is a sizable loss of lead which can significantly alter the stoichiometry and properties of the superconducting phase.