Stable {110} ⟨112⟩ textured Ag ribbons for biaxially-aligned YBa2Cu3O7-δ coated tapes

Texture development in pure Ag was investigated in order to obtain {110}< uvw > textured Ag ribbons that can be used as a substrate for YBa2Cu3O7 superconducting coated tapes without any buffer layer. The starting material was 99.95% pure commercial Ag foils. A 20% deformation reduction was used at each step of the cold rolling process after which an optimal annealing was achieved at 800 degrees C for 4 h in a primary vacuum. This process leads to large-grain ribbons with the {110}< 112 > orientation. A sharp and pure texture is obtained with a FWHM smaller than 6 degrees in the three x-ray pole figures that were used to calculate the orientation distribution function. Crystallographic orientation maps achieved by electron back-scattering diffraction show a misorientation from the normal direction of less than 4 degrees. A twinning mechanism is used to explain the formation of the {110}< 112 > texture. The stability of the {110}< 112 > texture is confirmed by further annealings up to 900 degrees C, a practical temperature for coated tapes preparation. Lengths up to 25 cm with a uniform {110}< 112 > texture have been obtained.