MOCVD and MOD of YBCO and Buffer Layers on Textured Metal Tapes

Abstract

Different layer architectures produced by only MOD, only MOCVD and combinations of MOD buffers and MOCVD YBCO are presented. RTR MOCVD-YBCO layers obtained on MOD CeO 2 MOD LZO Ni5at%W tapes demonstrate critical current densities up to 2 MA cm 2 at 77 K. On single LZO (50-100 nm) buffered Ni5at%W tapes from Nexans Superconductors and on RTR MOCVD buffer layers critical current densities between 0.8 and 1.3 MA/cm are obtained. RTR MOD-LZO layers often show delamination during YBCO deposition. Preannealing treatment before YBCO deposition allows to avoid this. Tapes up to 10 m are produced by combination of MOD-LZO and RTR MOCVD-YBCO.

Roughness and Texture of Epitaxial LZO Thin Films Grown on RABiTS Ni5W Substrates

“…New YBCO layer deposition by MOCVD has been done by the PerCoTech company (http://percotech.com/en/home) [12] on a sample annealed at 1020°C. The quality of this not very thick layer (350 nm) gave a transport current of the order of 1 MA/cm 2 .…”

“…LZO acts as a barrier against diffusion of the Ni toward YBCO [7,8] and must limit the oxidation during the different steps of the synthesis process of the coated conductor [9,10]. This buffer layer is used as a template to grow epitaxially the superconducting layer made of YBa 2 Cu 3 O 7 (YBCO) and for example deposited by MOCVD [11][12]. We focussed our studies on a simplified architecture composed of only the substrate, one LZO buffer layer and one YBCO superconducting layer.…”

Influence of laser power on orientation, microstructure and electrical performance of YBa2Cu3O7−x film prepared on (001) SrTiO3 single crystal substrate by spray atomizing and coprecipitating laser chemical vapor deposition

“…For preparation of the second generation high-temperature superconducting YBa 2 Cu 3 O 7 À x (YBCO) film, various techniques such as metalorganic deposition using trifluoroacetates [1], pulsed laser deposition [2], sputtering [3], molecular beam deposition [4], and metalorganic chemical vapor deposition (MOCVD) [5][6][7][8] have been attempted. Among these techniques, the MOCVD has been considered as a promising approach due to advantages of environment-friendly preparation process, uniform coverage, high controllability for film composition, large area coating for substrate with complex shape and relatively high deposition rate [5][6][7][8].…”

“…Among these techniques, the MOCVD has been considered as a promising approach due to advantages of environment-friendly preparation process, uniform coverage, high controllability for film composition, large area coating for substrate with complex shape and relatively high deposition rate [5][6][7][8]. More importantly, in industrial application, the MOCVD is a kind of low-cost vacuum technique that is suitable for scaling up in continuous preparation by a belt driven reel-to-reel system [9].…”

LZO, a Protective Barrier Against Oxidation of NiW Alloys

“…The fabrication of RABiTS ribbons is based on a bi-axially textured metal tape in which surface structure is transferred to the "YBCO" film by grain-to-grain epitaxy through an appropriate buffer film (somewhat complex architecture are often used). However, as YBCO deposition requires an oxidizing atmosphere at high temperature , the buffer layer needs to be an effective barrier against oxidation to protect efficiently the substrate [1]. Oxidation of the substrate is an obvious drawback to the mechanical properties of the conductor (fragility, possible delamination problems) but may also interfere with the YBCO purity.…”