Multifilament YBa2Cu3O6+x -coated conductors with minimized coupling   losses
  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. 
G. A. Levin, P. N. Barnes, J. W. Kell, N. Amemiya, Z. Jiang, K. Yoda,   and F. Kimura