Engineering nanocolumnar defect configurations for optimized vortex pinning in high temperature superconducting nanocomposite wires.
We report microstructural design via control of BaZrO3 (BZO) defect density in high temperature superconducting (HTS) wires based on epitaxial YBa2Cu3O7-δ (YBCO) films to achieve the highest critical current density, Jc, at different fields, H. We find the occurrence of Jc(H) cross-over between the films with 1-4 vol% BZO, indicating that optimal BZO doping is strongly field-dependent. The matching fields, Bφ, estimated by the number density of BZO nanocolumns are matched to the field ranges for which 1-4 vol% BZO-doped films exhibit the highest Jc(H). With incorporation of BZO defects with the controlled density, we fabricate 4-μm-thick single layer, YBCO + BZO nanocomposite film having the critical current (Ic) of ~1000 A cm(-1) at 77 K, self-field and the record minimum Ic, Ic(min), of 455 A cm(-1) at 65 K and 3 T for all field angles. This Ic(min) is the largest value ever reported from HTS films fabricated on metallic templates.
Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6116, USA. sunghunwee@yahoo.com
Sung Hun
SH
Wee
Yuri L
YL
Zuev
Claudia
C
Cantoni
Amit
A
Goyal
D003198:Computer Simulation; D004553:Electric Conductivity; D006358:Hot Temperature; D008422:Materials Testing; D008567:Membranes, Artificial; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008956:Models, Chemical; D008958:Models, Molecular; D036103:Nanotechnology / Q000379:methods; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size
D008567:Membranes, Artificial