Structure, texture and properties of yttrium high-temperature superconducting tapes

Cold deformation of a YBa2Cu3O7-x powder (123, Tc=90 K) and of plasticized bands manufactured from this powder and 2-10 vol.% of a rubber binder causes a partial decomposition of the phase 123 with an increase of the volume fraction of impurity phases, broadening of reflections, appearance of a tetragonal modification, and as a consequence, loss of the superconductivity at ≥ 77 K. Raw bands with 2-3 vol.% of the binder have a pronounced basal axial texture of the type (001) (110), which is favourable for the superconductivity. An increase of the binder quantity increases the volume of the impurity phases, lowers the pole density, and causes a partial scattering of the texture. Changes in the phase composition, structure, texture, and properties of the powder and bands upon heating up to 450-950 deg C depend on the annealing atmosphere (air, O2 or H2). Complete restoration of the superconductivity (to Tc=92 K) of the deformed HTSC powders and bands is observed upon annealing at 900-950 deg C in O2