Progress in Nanoengineered Microstructures for Tunable High‐Current, High‐Temperature Superconducting Wires

Abstract

High critical current densities (Jc) in thick films of the Y1Ba2Cu3O7–δ (YBCO, Tc ≈ 92 K) superconductor directly depend upon the types of nanoscale defects and their densities within the films. A major challenge for developing a viable wire technology is to introduce nanoscale defect structures into the YBCO grains of the thick film suitable for flux pinning and the tailoring of the superconducting properties to specific, application‐dependent, temperature and magnetic field conditions. Concurrently, the YBCO film needs to be integrated into a macroscopically defect‐free conductor in which the grain‐to‐grain connectivity maintains levels of inter‐grain Jc that are comparable to the intra‐grain Jc. That is, high critical current (Ic) YBCO coated conductors must contain engineered inhomogeneities on the nanoscale, while being homogeneous on the macroscale. An analysis is presented of the advances in high‐performance YBCO coated‐conductors using chemical solution deposition (CSD) based on metal trifluoroacetates and the subsequent processing to nano‐engineer the microstructure for tuneable superconducting wires. Multi‐scale structural, chemical, and electrical investigations of the CSD film processes, thick film development, key microstructural features, and wire properties are presented. Prospects for further development of much higher Ic wires for large‐scale, commercial application are discussed within the context of these recent advances.

Strong pinning in very fast grown reactive co-evaporated GdBa2Cu3O7 coated conductors

“…This is similar to what is observed in RE 2 O 3 excess Metal Organic Deposition (MOD) conductors Ref. 20. The difference though is that the conversion process using the RCE-DR process is much faster than the MOD process.…”

A hierarchically porous MgFe2O4/γ-Fe2O3 magnetic microspheres for efficient removals of dye and pharmaceutical from water

“…Kang et al [11] prepared nearly monodispersed hierarchical MgFe 2 O 4 to remove Pb (Ⅱ). In addition, multicomponent hybrid nanostructures have been reported as adsorbents for water treatment [12]. Su et al [13] synthesized Mg-doped Fe 3 with Mg on facilitating the dechlorination processes [13].…”

Importance of low-angle grain boundaries in YBa2Cu3O7−δcoated conductors

“…Progress using this technique has been rapid and high values of J c can be achieved in thick films [40,22], despite such films including a number of second phases and porosity. A comprehensive discussion of the progress and challenges involved in optimising such chemical solution deposited coated conductors is found in Holesinger et al [41]. As with the BaF 2 method, MOD-processed films have been noted to have a distinct layered rather than columnar microstructure [42].…”