In-field critical current and pinning mechanisms at 4.2 K of Zr-added REBCO coated conductors

The critical current and pinning mechanisms at 4.2 K have been studied over a magnetic field range of 0-14 T for Zr-added (0, 5 and 15 mol.%) REBa2Cu3O7-x(REBCO and RE = rare earth) coated conductors fabricated by advanced metal organic chemical vapor deposition (A-MOCVD). It is found that the (Ba + Zr)/Cu content in Zr-added (5 and 15 mol.%) REBCO affects the critical current at 77 K, 0 T as well as density, continuity and shape of BaZrO3(BZO) self-assembled nanocolumns and RE(2)O(3)in-plane precipitates that significantly enhance the pinning force densityFp(H) as well as isotropic pinning landscape at 4.2 K. In addition to bell-shape dependence of critical current density,J(c), at 4.2 K with (Ba + Zr)/Cu content we observed an unusualFp(H) behavior correlated to particular type of pinning centers, morphology and distribution that have been revealed by TEM microstructure analysis. By fitting the Dew-Hughes equation of the pinning force densityFp(H) at 4.2 K we extract the scaling behaviors of theFp(H) associated with the competition of pinning mechanisms driven by vertically-aligned BZO nanorods and in-plane RE(2)O(3)pinning defects. This result sheds light on approaches towards interactive control of strong and isotropic pinning centers in Zr-added REBa2Cu3O7-x(REBCO and RE = rare earth) coated conductors, and especially understanding the correlation between microstructural characteristics and vortex pinning mechanisms at 4.2 K in high magnetic fields.