Photo-assisted MOCVD fabrication of YBCO thick films and buffer layers on flexible metal substrates for wire applications

Photo-assisted MOCVD has been developed for application to high-rate, high quality YBa2Cu3O7-delta thin film production. This technique is now being a pplied to the fabrication of thick film YBa2Cu3O7-delta on flexible metal s ubstrates for wires and tapes. The unique application of photo-irradiation as the sole source of energy for the MOCVD reaction has resulted in extreme ly rapid growth rates for YBCO films with accompanying high superconducting performance. Typical YBCO films of thickness >1 mu m exhibit J(c) greater than or equal to 1 x 10(6) A/cm(2) and T-c > 90 K on single crystal oxide s ubstrates. Such films have now been integrated to metal substrates such as single crystal Ni(100) and roll-textured nickel foil. YBCO films gown on te xtured Ni foils with CeO2 and YSZ buffer layers show J(c) approximate to 3 to 5 x 10(5) A/cm(2) for films of 1 mu m thickness grown in 2 to 4 minutes time. Such performance for thick films made in such short growth time is pr omising for YBCO wire fabrication. The development of effective YBCO wire t hrough thick film growth on flexible substrates also requires buffer layer application. Photo-assisted MOCVD has also been applied to buffer layer for mation with promising results.