A number of experimental and theoretical studies have been performed to understand the mechanism of high-Tcsuperconductivity and to enhance Tc. High-pressure techniques have played a very important role for these studies. In this paper,the high-pressure techniques and physical properties of high-Tc superconductor under high pressure are presented.
Superconducting filaments in composite wires/tapes are subjected to residual stresses arising from the mismatch of the coefficient of thermal expansion among the constituents, tensile and bending stresses during winding, and electromagnetic (Lorentz) force during operation. Such stresses affect the superconducting properties due to the change in strain itself and stress-induced damage. The present article reviews the recent experimental and analytical results on the accumulation of residual strain in the sample length direction (current transport direction). In addition, this article reviews the prediction of strain dependence for critical current with applied tensile/bending strain from tensile stress-strain curve in the multifilamentary BSCCO-superconducting composite tapes.