REBCO-based conductors for large-scale HTS applications: Exploring limits of performance in coated conductors

Joint Technical Seminar of IEEE Tallahassee Section and FAMU-FSU College of Engineering
Title: REBCO-based conductors for large-scale HTS applications: Exploring limits of performance in coated conductors
Presenter: Dr. Amit Goyal, Professor, SUNY at Buffalo, Member, National Academy of Engineering
Time: 3:00 pm – 4:30 pm, Thursday, June 27, 2024
Location: Room 120, Center for Advanced Power Systems, 2000 Levy Avenue, Tallahassee, Fl 32310
Refreshments will be served
Abstract
Current status related to commercialization of three platform technologies will be discussed: (1) Rolling-Assisted-Biaxially-Textured Substrates; (2) LMOe-enabled IBAD MgO Substrates technology, for fabrication of kilometer-long HTS wires and (3) Phase Separation and Strain-driven Self-Assembly technology for creating controlled nanostructures in high-performance, kilometer-long wires. A majority of companies world-wide use one or more of these technologies for fabricating kilometer-long, high-performance, single-crystal-like HTS wires. However, the price/performance metric of coated conductors is not yet favorable for most large-scale applications. A key route to making the price/performance metric of HTS wires more favorable is to significantly enhance the critical current density, Jc (H,T) of coated conductors.
Engineered nanoscale defects within REBa2Cu3O7-δ (REBCO) based coated conductors are of great interest for enhancing the performance via vortex-pinning, especially in high-applied magnetic fields. We have previously reported excellent Jc’s and flux-pinning in YBCO films with self-assembled BZO columnar defects in the entire operating temperature regime from 4.2K-77K via correlated pinning from extended defects at mid to higher operating temperatures as well as collective pinning from oxygen point defects arising due to the local strain near YBCO/BZO interfaces at lower operating temperatures. We will report on our recent work to probe the limits of critical current density possible via defect engineering. We have obtained record values of critical current density, Jc, and pinning force, Fp, in REBCO coated conductors with self-assembled BZO nanocolumns fabricated using pulsed laser ablation. A Jc of ~ 190 MA/cm2 at 4.2K, self-field and ~ 90 MA/cm2, at 4.2K, 7T was measured. At 20K, Jc of over 150 MA/cm2 at self-field and over 60 MA/cm2 at 7T was observed. A very high pinning force, Fp, of ~ 6.4 TN/m3 and ~ 4.2 TN/m3 were observed at 7T, 4.2K and 7T, 20K respectively. These are the highest values of Jc and Fp reported to date. These results establish that significant performance enhancements are still possible and hence the associated reduction in costs that could potentially be realized in optimized, commercial HTS wires. In addition, we have experimentally confirmed the effect of local micro-strain resulting in oxygen point defects due to the large lattice-misfit between REBCO and BZO as well as the effect of Ca-doping in REBCO coated conductors to mitigate the microstrain. These results can help guide industry towards realizing significantly higher performance in commercial coated conductors or HTS wires.
Speaker(s): , Prof. Amit Goyal
Room: 120, Bldg: A, 2000 Levy Ave. , Tallahassee, Florida, United States, 32310