Long IBAD-MgO and PLD coated conductor

Abstract Simple 4-layered buffer architecture of Ion Beam Assisted Deposition (IBAD)-MgO is proposed. Using a new barrier and nucleation layer of amorphous Gd 2 Zr 2 O 7 (GZO) and self-epitaxy of PLD-CeO 2 layer, the new 4-layered structure, GZO/IBAD-MgO/LaMnO 3 (LMO)/CeO 2 , was realized, which decreased the number of buffer layers by one layer compared to the conventional 5-layered IBAD-MgO structure. Self-epitaxial CeO 2 layer developed the in-plane grain texturing in the order of 3–4°. Several tens meter long IBAD-MgO substrates were fabricated by a reel-to-reel method at the production speed of 24 m/h for IBAD-MgO. Using this highly textured substrate, a 41 m long GdB 2 Cu 3 O x (GdBCO) coated conductor was fabricated. The conductor exhibited high in-plane texturing degree around 4° and high I c values of 500–600 A at 77 K and self-field. Furthermore, improvement in production speed of each buffer layers was carried out: a new IBAD-MgO technique by DC-reactive sputtering brought about a high production rate of 150 m/h in spite of the small deposition area (6 × 20 cm 2 ) and exhibited a high I c value of 286 A; PLD-CeO 2 and sputter LMO were also improved in the production speed by the multi-turn method and the deposition temperature control, respectively.