Grain boundary networks in high-performance, heteroepitaxial, YBCO films on polycrystalline, cube-textured metals
- ORNL
- Washington State University
- Institute of Physics, Augsburg University, Augsburg, Germany
Grain boundaries (GBs) in high-temperature superconductors suppress the critical current density (Jc) dramatically [1-3]. The Jc drops exponentially when GB-misorientation exceeds 4 [3]. To reduce the number of high-angle GBs, fabrication of biaxially-textured, superconducting wires via epitaxial growth on cube-textured metals has been widely investigated [4-6]. Such wires have exhibited very high-Jc in applied magnetic fields despite having a majority of GBs with total misorientations greater than 4 . Here we show that GB networks in these wires have numerous GBs with out-of-plane misorientations > 4 and few boundaries having in-plane misorientations > 4 . The high performance can be explained if the Jc is determined primarily by in-plane misorientations. This supposition was confirmed by in-field transport measurements on artificially fabricated bicrystals of superconductors having only out-of-plane misorientations. Atomic resolution imaging of bicrystals with out-of-plane misorientations show that superconducting ab-planes are continuous across such GBs in contrast to GBs with in-plane misorientations.
- Research Organization:
- Oak Ridge National Laboratory (ORNL); Shared Research Equipment Collaborative Research Center
- Sponsoring Organization:
- OE USDOE - Office of Electric Transmission and Distribution
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1010554
- Journal Information:
- Philosophical Magazine Letters, Journal Name: Philosophical Magazine Letters Journal Issue: 4 Vol. 91; ISSN 0950-0839
- Country of Publication:
- United States
- Language:
- English
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