Small and repetitive axial strain reducing the critical current in BSCCO/Ag superconductors

The critical current in two types of axially deformed BSCCO/Ag tape conductors is investigated. An Ic reduction is observed for small axial strains (ranging from 0 to 0.3%) with a characteristic slope dic/d&epsiv;=-5±1 (relative Ic, change per relative change in length). In the case of an axial compression there is a more pronounced Ic reduction. For small axial strains (<0.3%) a certain reversible change in Ic is observed. This reversible behaviour occurs in combination with an irreversible reduction that increases when the number of strain cycles is increased. The reversible part of the Ic change remains for a large number of strain cycles (>10000) and has a similar negative slope for both compressive and tensile strains. It is proposed that the reversible Ic change is correlated to a non-hydrostatic lattice deformation. The Ic versus strain behaviour is in good agreement with an earlier proposed model