Photo-assisted MOCVD growth of YBCO thick films for wire applications

Photo-assisted MOCVD has been applied to the fabrication of thick film YBa2Cu3O7-x, for wires and tapes. The application of photo-irradiation as the sole source of energy for the MOCVD reaction has resulted in extremely rapid growth rates for YBCO films with high superconducting performance. Typical YBCO films of thickness >1 mum exhibit J(c)similar to1 x 10(6) A cm(-2) and T-c>90 K on single crystal oxide substrates. Such films have now been integrated to metal substrates including both single crystal Ni(100) and roll-textured nickel foil. YBCO films grown on these substrates with CeO2 and YSZ buffer layers show J(c)>3 x 10(5) A cm(-2) for films of > 1 mum thickness grown in 2-4 min time. Such performance for thick films made in such a short time is promising for YBCO wire fabrication with optimization of the photo-assisted MOCVD process expected to yield J(c)>1 x 10(6) A cm(-2) for 1-5 mum thick YBCO films on flexible nickel substrates. (C) 1998 Elsevier Science Ltd. All rights reserved.