Multifilament YBa2Cu3O6+x -coated conductors with minimized coupling losses

TL;DR

This paper presents an experimental method to produce multifilament YBa2Cu3O6+x coated conductors with significantly reduced coupling losses in varying magnetic fields by using oxygen exposure to insulate filaments.

Contribution

The study demonstrates a novel oxygen treatment process that effectively insulates filaments, drastically reducing coupling losses compared to previous laser ablation methods.

Findings

Coupling losses are negligible across tested magnetic field amplitudes and frequencies.

Oxygen exposure creates high resistivity oxides insulating the filaments.

The method improves the performance of multifilament coated conductors in dynamic magnetic environments.

Abstract

We report an experimental approach to making multifilament coated conductors with low losses in applied time-varying magnetic field. Previously, the multifilament conductors obtained for that purpose by laser ablation suffered from high coupling losses. Here we report how this problem can be solved. When the substrate metal in the grooves segregating the filaments is exposed to oxygen, it forms high resistivity oxides that electrically insulate the stripes from each other and from the substrate. As the result, the coupling loss has become negligible over the entire range of tested parameters (magnetic field amplitudes B and frequencies f) available to us.