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Oxygen stoichiometry and properties of Pb-substituted Bi2Sr2CaCu2O8 + δ

Research paper by I. B. Bobylev, N. A. Zyuzeva, I. L. Deryagina, L. N. Kuz’minykh, E. P. Romanov

Indexed on: 01 Nov '00Published on: 01 Nov '00Published in: Inorganic Materials



Abstract

The effect of partial Pb substitution for Bi on the oxygen stoichiometry and superconducting properties of Bi2Sr2CaCu2O8+δ was studied. The Pb content and heat-treatment conditions were optimized to attain the highest critical parameters. The observed changes in the superconducting properties were shown not to correlate with oxygen stoichiometry. Superconducting properties were found to persist in the absence of Cu in the formal oxidation state 3+. A reduction in the concentration of excess oxygen to about the lowest possible level is accompanied by a significant increase inTcR = 0 (96 K) and critical current density. The possible mechanisms underlying the effect of Pb substitution on the properties of 2212 are discussed.