Direct evidence of the high strain tolerance of the critical current of DI-BSCCO tapes fabricated by means of the pretensioned lamination technique

A remarkable improvement in the strain dependence of critical current and the mechanical properties of DI-BSCCO-Bi2223 tapes was achieved by means of the pretensioned lamination technique. In order to elucidate the origin of this high performance, the local strain exerted on BSCCO filaments was investigated by means of the synchrotron radiation technique. The relaxation strain Ar was expressed by the sum of thermal strain and tensile strain in the fracture of BSCCO filaments. It was concluded that the central parameter when considering the improvement of strain induced properties is the force free strain exerted on BSCCO filaments together with their own strength.