| J. L. MacManus-Driscoll, S. R. Foltyn, Q. X. Jia, H. Wang, A. Serquis, L. Civale, B. Maiorov, M.E. Hawley, M.P. Maley and D. E. Peterson
This study presents a method to significantly enhance the in-field current densities (Jc) of YBa₂Cu₃O₇₋x (YBCO) superconducting coated conductors by incorporating BaZrO₃. The approach involves modifying the composition of ceramic targets used in pulsed laser deposition (PLD) to include BaZrO₃. This results in a 1.5 to 5-fold improvement in Jc at 75.5 K, demonstrating a practical and scalable method for enhancing pinning in superconducting tapes.
The enhancement in Jc is attributed to the introduction of defects such as dislocations and nano-particles of BaZrO₃. These defects act as pinning centers for magnetic flux lines, improving the critical current density. The BaZrO₃ particles are heteroepitaxially grown within YBCO films and are easily incorporated from a mixed ceramic target. The particles lead to significant improvements in Jc on both single crystal and buffered metallic substrates.
X-ray diffraction and transmission electron microscopy reveal that BaZrO₃ particles are in-plane aligned with YBCO, forming a family of correlated linear defects that contribute to uniaxial pinning along the c-axis. The lattice mismatch between BaZrO₃ and YBCO introduces strain, which enhances pinning. The presence of these defects, along with columnar defects, leads to a substantial increase in Jc, with values exceeding 0.1 MA/cm² at 4.5 T in 1 μm thick films.
The study also shows that the addition of BaZrO₃ increases the irreversibility field, indicating improved pinning. The results demonstrate that the method is effective across a wide range of magnetic fields, with Jc values up to 5 times higher at 7 T. The findings suggest that other heteroepitaxial second phases and concentrations could lead to even greater enhancements in pinning, making this approach a promising strategy for improving the performance of superconducting coated conductors.This study presents a method to significantly enhance the in-field current densities (Jc) of YBa₂Cu₃O₇₋x (YBCO) superconducting coated conductors by incorporating BaZrO₃. The approach involves modifying the composition of ceramic targets used in pulsed laser deposition (PLD) to include BaZrO₃. This results in a 1.5 to 5-fold improvement in Jc at 75.5 K, demonstrating a practical and scalable method for enhancing pinning in superconducting tapes.
The enhancement in Jc is attributed to the introduction of defects such as dislocations and nano-particles of BaZrO₃. These defects act as pinning centers for magnetic flux lines, improving the critical current density. The BaZrO₃ particles are heteroepitaxially grown within YBCO films and are easily incorporated from a mixed ceramic target. The particles lead to significant improvements in Jc on both single crystal and buffered metallic substrates.
X-ray diffraction and transmission electron microscopy reveal that BaZrO₃ particles are in-plane aligned with YBCO, forming a family of correlated linear defects that contribute to uniaxial pinning along the c-axis. The lattice mismatch between BaZrO₃ and YBCO introduces strain, which enhances pinning. The presence of these defects, along with columnar defects, leads to a substantial increase in Jc, with values exceeding 0.1 MA/cm² at 4.5 T in 1 μm thick films.
The study also shows that the addition of BaZrO₃ increases the irreversibility field, indicating improved pinning. The results demonstrate that the method is effective across a wide range of magnetic fields, with Jc values up to 5 times higher at 7 T. The findings suggest that other heteroepitaxial second phases and concentrations could lead to even greater enhancements in pinning, making this approach a promising strategy for improving the performance of superconducting coated conductors.