Researchers at the University at Buffalo have developed a superconducting wire segment based on rare-earth barium copper oxide (REBCO) that sets new records for current density and pinning force. The wire, only 0.2 microns thick, can carry an impressive 190 MA/cm2 in the absence of magnetic fields at 4.2 K, and still manage over 150 MA/cm2 at warmer temperatures of 20 K.
These figures are remarkable considering the commercial superconducting wires that are almost 10 times thicker. The high-temperature superconducting (HTS) wire has potential applications in energy generation, storage, transmission, transportation, defense, and medical sectors. Its development could address the world’s energy supply issues, according to Amit Goyal of the University at Buffalo.
The new HTS wire boasts record-breaking critical current density values at lower operating temperatures ranging from 4.2-30 K, which is crucial for commercial nuclear fusion applications. Additionally, it has the highest pinning force ever reported for such wires, with values of around 6.4 TN/m3 per cubic meter at 4.2 K and about 4.2 TN/m3 at 20 K under a 7 T applied magnetic field.
The researchers used pulsed laser deposition to create the wire, which involves ablation material on a target and depositing it as a film on a substrate. The high critical current density was made possible by a combination of pinning effects from rare-earth doping, oxygen-point defects, and insulating barium zirconate nanocolumns.
This breakthrough has significant implications for the HTS field, with commercial nuclear fusion being an important niche application. One company, Commonwealth Fusion, has already invested $1.8 billion in series B funding to commercialize this technology. The researchers believe that further performance enhancements are still possible and that their work is just the beginning of a new era for HTS wires.
Source: https://physicsworld.com/a/new-superconductor-has-record-breaking-current-density/