The effect of Sb concentration on the superconducting properties and phase composition of Bi-Pb-Sb-Sr-Ca-Cu oxide materials

The effect of Sb superconducting materials with nominal composition Bi_1.6Pb_0.4–x Sb _x Sr₂Ca₂Cu₃O _y (x=0.01–0.14) and Bi_1.5Pb_0.5–x Sb _x Sr₂Ca₂Cu₃O _y (x=0.025–0.12) has been investigated. These materials were subjected to DTA, ICP emission spectrometry, SEM, XRD and electric resistance measurements. It was found that the introduction of Sb raises the melting temperature of the material, it also raisesT _c (up to 110K) at several defined stoichiometric ratios. A certain lack of correspondence between the 2223 phase volume and theT _c value was noticed and a possible explanation has been proposed.