Overcoming the barrier to 1000 Acm width superconducting coatings

Remarkable progress has been made in the development of Y Ba2 Cu3 O7-δ (YBCO)-based coated conductors, and the problems of continuous processing of commercially viable tape lengths are being rapidly solved by companies around the world. However, the current carried by these tapes is presently limited to about 100 A for a 1-cm -wide tape, and this is due to a rapid decrease of critical current density (Jc) as the coating thickness is increased. We have now overcome this problem by separating relatively thin YBCO layers with very thin layers of Ce O2. Using this multilayer technology, we have achieved Jc values on metal substrates of up to 4.0 MA cm2 (75 K, self-field) in films as thick as 3.5 μm, for an extrapolated current of 1400 Acm width.