Enhancement of critical current density using assit pinning centers in high-Tc superconducting thin films with 1D pinning centers

采用200 MeV Xe离子沿c轴方向辐照制备了BaZrO3/YBa2Cu3Oy准多层膜，控制了BaZrO3纳米粒子的尺寸和空间分布。当BaZrO3纳米粒子的尺寸较大时，未被cd捕获的磁通线（如cd之间的间隙磁通线和双结磁通线）可以被BaZrO3纳米粒子更有效地钉住，从而增强了高磁场和高温下的Jc。此外，在高温下，随着磁场的增加，纳米粒子的相关排可能偏离c轴，Jc值与n值呈现负相关关系。这表明，混合通量钉钉不仅取决于一维钉钉中心和三维钉钉中心的结合，还取决于三维钉钉中心的大小和空间分布。

BaZrO3/YBa2Cu3Oy quasi-multilayered films, in which the size and the spatial dirstribution 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.