High pressure studies of the superconducting transition in (Bi,Pb)2Sr2Ca2Cu3O10

The superconducting transition for a bismuth-lead superconductor has been investigated at helium pressures to 500 MPa. The form of the resistance transition is similar at all pressures and shows a marked discontinuity at about 107.5 K for the material investigated. The characteristic temperature defining the T(c) transition initially falls at 100 MPa and then increases at 200 MPa. Somewhere above 200 MPa the normal resistance increases more rapidly and also irreversibly. Repeated cycling above 200 MPa generates a small resistance in the sample at temperatures below the onset temperature. This is apparently caused by pressure-induced slip or fracture. The normal resistance around 120 K increases systematically with pressure and temperature.