Angular dependence of critical current density and n-values in BaZrO3/YBa2Cu3Oy quasi-multilayered films with columnar defects

• BZO/YBCO multilayered films were irradiated using 200 MeV Xe ions along c-axis.
• Size and spatial distribution of particles were tuned by the growth temperature.
• The difference in growth temperatures stand out on the Jc(θ), especially for high B.
• A shoulder behaviour occurs on the Jc(θ) in the multilayered films with CDs.
• The inverse correlation between Jc and n-value emerges around B||c at high T.

BaZrO3/YBa2Cu3Oy quasi-multilayered films, in which the size and the spatial distribution of BaZrO3 nano-particles were controlled, were irradiated using 200 MeV Xe ions along the c-axis direction. When the BaZrO3 nano-particles were larger in size, the flux lines not captured by CDs, such as interstitial flux lines between CDs and double kinks of flux lines, can be pinned more effectively by the BaZrO3 nano-particles, so that the Jc enhances for high magnetic fields and high temperature. In addition, the inverse correlation between Jc and n-value appears at high temperature in increasing magnetic field for the film with correlated rows of the nano-particles which might be curved off the c-axis. These suggest that the hybrid flux pinning depends not only on the combination of one-dimensional (1D) and three-dimensional pinning centers (3D-PCs) but also on the size and the spatial distribution of the 3D-PCs.