Effect of sintering temperature on superconducting properties of Bi₂Pb₂Sr₂Ca₂Cu_3-xCo_xO_10+δ system

Abstract

Bi2Pb0.3Sr2Ca2Cu3-xCoxO10+δ high temperature superconductors with x=0, 0.2 and 0.4 were prepared by a solid state reaction method. The samples properties have been investigated structurally by X-ray diffraction and morphologically by scanning electron microscopy. Structural analysis showed that two superconducting phases coexist in the samples high temperature Bi-2223 and low-temperature phase 2212 with orthorhombic structure for all samples. Four point probe method was used to study the electrical properties of the samples and all of them showed superconductivity behavior. The transition temperature increases with the increasing Co concentration and sintering temperature. Bi2Pb0.3Sr2Ca2Cu3-xCoxO10+δ superconductor sintered at 130 0C shows highest critical temperature 114 K.