Correlation between in-field critical currents in Zr-added (Gd, Y)Ba₂Cu₃Oxsuperconducting tapes at 30 and 77 K

Critical current ( I c ) values of 1384 A/12 mm, corresponding to a critical current density of 12.47 MA cm −2 and a pinning force of 374 GN m −3 , have been achieved at 30 K, 3 T in the orientation of field parallel to the c axis ( B ∥ c ) in (Gd, Y)BaCuO tapes with 15 mol% Zr addition made by metal organic chemical vapor deposition (MOCVD). These tapes show pinning force levels as high as 453 GN m −3 at 30 K. An analysis of the properties of 24–28 (Gd, Y)BaCuO tapes with 15 mol% Zr addition showed a lack of correlation between their critical currents at 30 K, 3 T ( B ∥ c ) and I c values both at 77 K, zero field and at 77 K, 1 T ( B ∥ c ). However, a strong correlation was found between the critical currents at 30 K, 3 T and at 77 K, 3 T ( B ∥ c ). It has also been discovered that the minimum critical current ( I c, min ) value at 77 K, 3 T has no influence on the I c, min value at 30 K, 3 T, and it in turn depends on the ratio of the I c values in the orientations of field parallel and perpendicular to the c axis at 77 K, 3 T.