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Four 5 mm wide YBCO conductors were assembled face to face to obtain a stacked YBCO conductor (YBCO stack). The space between the conductors composing the YBCO stack was set at 1.0 mm to investigate the influence of the space on AC loss characteristics. The magnetization losses without transport current, the transport losses without external magnetic field, and total AC losses of the YBCO stack carrying various transport currents in transverse magnetic fields with various orientations were measured. The measured AC losses in the YBCO stack were compared with those in a 0.2 mm space YBCO stack composed of the same conductors used in the 1.0 mm space YBCO stack as well as a single YBCO conductor. Magnetization loss without transport current in a YBCO stack decreases with decreasing space between the conductors in low and intermediate magnetic field. Transport loss without external magnetic field in a YBCO stack increases with decreasing space between conductors. There are three characterized regions, when comparing the total AC losses in the two YBCO stacks with different space between the conductors composing the stacks: (a) in the low magnetic field region, the total AC losses in the YBCO stack with smaller space are larger than those in the YBCO stack with larger space, (b) in the intermediate magnetic field region, the total AC losses in the YBCO stack with smaller space are larger than those in the YBCO stack with larger space, (c) in the high magnetic field region, the total AC losses in both YBCO stacks agree well with those in the single YBCO conductor as well as Brandt and Indembom’s analytical values.

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Ion-beam-assisted deposition (IBAD) has been used to prepare biaxially textured templates necessary to realizing high superconducting performance in coated conductors. The IBAD method is characterized by the direct deposition of sharply aligned templates on nontextured metal substrates using fluorite-like oxide films (yttrium-stabilized zirconia, Gd 2 Zr 2 O 7 , etc.). Recent progress in vacuum technology for IBAD has made it possible to reproducibly fabricate long lengths (100 m) of IBAD-GZO templates. Continuous deposition of YBCO films on these templates has been achieved by pulsed laser deposition (PLD). Furthermore, a new approach to improving the texture of IBAD templates was found by using CeO 2 films grown by PLD. Trifluoroacetate-based metalorganic deposition has also been used instead of PLD to produce superconducting layers on IBAD buffered tapes, aiming at a low-cost process. This article reviews progress in the research and development of biaxially textured templates produced using IBAD and their subsequent use in fabricating superconducting tapes and wires by means of several processes.

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