HIPped High Density Bi-(Pb)-Sr-Ca-Cu-O Superconductors Produced without Any Additional Treatment

Abstract

Superconducting ceramics (BiSrCaCu₂O _x and BiPb _y SrCaCu₂O _x ) were directly obtained for the first time by a hot isostatic press (HIP) densification without any additional treatment. The ceramics obtained from BiSrCaCu₂O _x were 85 K superconductors and the ones obtained from BiPb _y SrCaCu₂O _x had a high-T _c phase, which was not observed before the HIP process. The HIPped BiSrCaCu₂O _x samples were densified to 5600 kg/m³, and with PbO additions, the density was around 6000 kg/m³. All the conventionally processed samples had a lower T _c,zero of 65 K and lower densities of about 4600 kg/m³. A remarkable improvement in crystallinity and sharper superconducting transition were achieved through the HIP densification process without any additional treatment.