High-Performance Superconducting Wires via Strain-Driven Self-Assembly for Large-Scale Applications in Energy Generation, Transmission and Storage

Engineered nanoscale defects within REBa2Cu3O7-δ (REBCO) based coated conductors or epitaxial heterostructures are needed for enhancing vortex-pinning, especially in high-applied magnetic fields. We have conducted extensive research to optimize vortex-pinning and enhance supercurrent capacity via controlled introduction of various types of nanoscale defects at nanoscale spacing via a phase-separation and strain-driven self-assembly process. This talk will provide an overview on how density, morphology, and composition of engineered nanoscale, columnar defects effects vortex-pinning in different temperature, field and angular regimes. Detailed microstructural and superconducting properties enabled by these engineered defects will be presented. We also show that controlled Ca-doping can modulate local microstrain around non-superconducting, verticallyoriented, BZO nano-columns (due to REBCO and BZO lattice-mismatch) as revealed via highresolution HRTEM. Correlated with measured local microstrain and high-spatial resolution electron-energy loss (EELS) spectroscopy of both O and Cu edges reveal local modulation of oxygen non-stoichiometry resulting in oxygen point defects in the presence of microstrain. These oxygen point defects and vertically-oriented, heteroepitaxial columnar defects provide significant vortex-pinning in a broad operating temperature regime from 4.2K to 77K. The talk will discuss how various large-scale applications in energy generation (including commercial nuclear fusion), energy transmission, energy storage and energy-efficient devices are impacted and enabled by these high-performance, nanostructured HTS wires.