Deformation Effects on the Structure and Properties of Y1−xCaxBa2Cu3O7−δ (x=0;0.3) Tapes Produced by OPIT Method in the Ag-Tube

Samples of superconducting tapes with two type cores (YBa2Cu3O7−y and Y0.7Ca0.3Ba2Cu3O7−δ ), obtained by the OPIT method under two different regime of rolling—cold (20 °C) and hot (825 °C) are investigated. The superconducting core materials were prepared by standard solid-state technology and fill in the high purity (4N) Ag-tubes. The effect of cold and hot rolling deformation on the orientation of supercoducting crystals were studied by XRD analysis. It was found that a higher degree of texturing in the out of plane direction is obtained after hot rolling deformation in tapes with overdoped core. As a result, the highest critical current density (J c ) at 77 K and zero magnetic field was achieved in them. J c increases with the time in the superconducting tapes, which is connected probably with the releasing of stress between the superconducting core and Ag sheat.