PLD-IBAD法YBCO超電導線材の開発自己配向成長したCeO2膜を利用したYBa2Cu3O7-x超電導線材の開発

In order to fabricate a YBa2Cu3O7−x(YBCO) coated conductor with high critical current density, Jc, we have been investigating the pulsed laser deposition (PLD) processing using the “self-epitaxial ” PLD-CeO2 layer on an ion beam assisted deposition (IBAD)-Gd2Zr2O7 (GZO) buffered Hastelloy tape. For the study using short samples with 10 mm in length and 10 mm in width, the Jc value of YBCO increased exponentially with decreasing the in-plane grain alignment of YBCO and CeO2 layers, and then the Jc value of 4.4×1010 A/m2 was attained at the delta phi value of 2.4 degrees. Furthermore, we also succeeded in deposition of high Jc and thick YBCO film; the thickness of 1.2 μm and the Jc value of 2.3×1010 A/m2. This value corresponds to 276 A/cm-width. Based on these results, 0.9 m to 10 m long YBCO coated conductors were fabricated using the reel-to-reel system. Consequently, Ic and Jc values attained 36.4 A and 7.3×109 A/m2 in the 0.9 m long sample with the thickness of 0.5 μm and 20.5 A and 5.4×109 A/m2 in the 4.5 m long sample with the thickness of 0.38 μm, respectively.