Аннотация:A new enlarged single source MOCVD system for the deposition onto moved tapes was constructed.
Computer simulations (FLUENT 5.1) were used for the scale up of the existing small tape reactor.This new system can continuously coat Ni-tapes with a velocity of 4 m/h to produce a coating
thickness of 300-350 nrn. YBCO-films (300-350 nm thick) deposited on moved (4 mh) single crystalline
LaA103 and BAD buffered substrates exhibit j,(77 K) > 4 ~~canmd j,(-77 ~K) > 2 MAC~Iw-i~th good
crystalline quality. The local deposition rate in the hot wall reactor was 5-12 pm/h.
Oxide buffer layers (CeO2, Y203, LaCr03 and LaMnO3 )were deposited by MOCVD in reducing
atmosphere on single crystalline substrates in epitaxial quality. On textured Ni coated with Ce02 no NiO was measured by XRD after deposition. The films were (001)Ce02-textured and without carbon
contamination (WDX). The morphology of the Ce02 buffer layer must be optimised for YBCO
deposition.
Textured NiO was epitaxially grown onto textured Ni. Oriented MgO buffer layers were deposited
onto the NiO. The YBCO film on this buffer layer system was superconducting with a Tc = 86 K and a
critical current density of 104A/cm2 at 77 K.
The results promise the possibility of buffer layer and YBCO deposition on textured Ni tapes in a
MOCVD set-up. The quality of the buffer layers and the YBCO on textured Ni must be further improved.