We investigated the flux pinning properties of nano-rods comprised of BaZrO3 and BaSnO3 in REBa2Cu3O7-δ (REBCO, RE: rare earth elements) thin films. The doping amounts of BaZrO3 in YBa2Cu3O7-δ thin films and BaSnO3 in ErBa2Cu3O7-δ thin films were varied with 0-3.5 wt% and 2.0-4.0 wt%, respectively. The in-field critical current density of 1.5 wt%-BaZrO3-doped YBa2Cu3O7-δ film was higher than those of any other samples measured in this study. The α values in the relation of Jc-B-α are 0.2-0.3 for the BaZrO3- and BaSnO3-doped films. This fact shows the introduction of nano-rods is effective for the less magnetic field dependence of Jc. As one of the important results, it was found that the introduction of nano-rods caused the peak or kink in the magnetic field dependence of the pinning parameter m which was derived from the scaling of current-voltage characteristics. This phenomenon is the sign of the flux pinning due to the one-dimensional pinning centers. The peak fields of the BaSnO3-doped films were slightly lower than those of the BaZrO3-doped films, though the dope levels of the BaSnO3-doped films were higher. This suggests that the diameter of BaSnO3 nano-rods is larger than that of BaZrO3 ones.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering