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High critical current (Ic) in high magnetic fields (B) with minimal variations with respect to the orientation of the B field is demanded by many applications such as high-field magnets for fusion systems. Motivated by this, this work studies 6 vol. % BaZrO3/YBa2Cu3O7 (BZO/YBCO) multilayer nanocomposite films by stacking two 10 nm thick Ca0.3Y0.7Ba2Cu3O7 (CaY-123) spacers with three BZO/YBCO layers of thickness varied from 50 to 330 nm to make the total film thickness of 150–1000 nm. The Ca diffusion from the spacers into BZO/YBCO was shown to dramatically enhance pinning efficiency of c-axis aligned BZO nanorods, which yields high and almost thickness independent critical current density (Jc) in the BZO/YBCO multilayer nanocomposite films. Remarkably, enhanced Jc was observed in these multilayer samples at a wide temperature range of 20–80 K and magnetic fields up to 9.0 T. In particular, the thicker BZO/YBCO multilayer films outperform their thinner counterparts in both higher value and less anisotropy of Jc at lower temperatures and higher fields. At 20 K and 9.0 T, Ic is up to 654 A/cm-width at B//c in the 6% multilayer (1000 nm) sample, which is close to 753 A/cm-width at B//ab due to the intrinsic pinning. This result illustrates the critical role of the Ca cation diffusion into the YBCO lattice in achieving high and isotropic pinning in thick BZO/YBCO multilayer films. 

Nanoscale c-axis-aligned one dimensional artificial pinning centers (1D-APC) in superconducting YBa2Cu3O7-x (YBCO) films have been shown to provide strong correlated pining to magnetic vortices at magnetic field H//c-axis. A question arises on how the pinning effectiveness is sustained as the H-orientation (θ) deviates from the c-axis and how such an angular range is correlated to the pinning efficiency of an individual 1D-APC. To shed lights on this question, this work investigates the angular range of pinning effectiveness of the BaZrO3 (BZO) 1D-APCs in BZO/YBa2Cu3O7-x nanocomposites as the strain field overlap is systematically varied by increasing the BZO doping level in the range of 2-6 vol.% and by the introduction of the secondary Y2O3 nanoparticles (3D APCs). By evaluating the maximum pinning force density (Fp, max), its location Hmax, and the α values of the nanocomposites normalized to that of the reference YBa2Cu3O7-x film as functions of θ at temperatures of 65–77 K, a quantitative correlation between the pinning efficiency of the BZO 1D-APCs and their effective angular range was obtained. In most samples, the 1D-APCs can provide enhanced Hmax in the range of θ ∼0°-60°. However, the Fp, max values only in nanocomposites with high pinning efficiency 1D-APCs exceed that of the YBa2Cu3O7-x over a smaller range up to θ ∼ 37°. Finally, the introduction of 3D APCs results in reduction of the α values over nearly the entire angular range. This study reveals the importance in improving individual 1D-APC’s pinning efficiency and hence extending its angular range of effective pinning.