Transversal compressive force and superconducting transition properties of Bi-2223 tapes

Transversal compressive force was applied to a face of Bi-2223 tape, and V-I characteristics and mechanical properties of the tape were measured. Contact conditions between the tape and pushing parts are two kinds (a line-contact and a face-contact). Based on measured data dependence of critical currents and n-values of the Bi-2223 tape on the transversal compressive force and deformation of the tape was experimentally studied. From the results of the line-contact condition between the tape and the pushing parts, 25 N of the force to the tape decreased the critical current and the thickness of the tape by 90% and 0.6% of the initial value, respectively. The data under the face-contact condition showed little degradation of the tape's critical currents because of the small stress to the tape. After those experiments the tape was cut along the longitudinal direction of the tape and Bi filaments were observed microscopically in the cross-section. (C) 2003 Elsevier B.V. All rights reserved.