Recent progresses in R&D of the TFA-MOD process for coated conductors are reviewed. On the efforts for high Ic tapes, the new process to prevent the crack formation in the thick film, which is the intermediate annealing between the calcination and the crystallization steps, was developed. Additionally, control of the starting composition, especially for the Ba-poor composition from the Y:Ba:Cu = 1:2:3 stoichiometric one, is found to be effective to improve the Jc value of the films. Consequently, the extremely high Ic value of 735 A was obtained. On the other hand, a reel-to-reel system has been applied to fabricate long tapes. A reasonable long tape of 25 m with 100 A was obtained by the increase of the gas flow rate which assists to enhance the conversion reaction rate. Additionally, it was found that the rigorous humidity control in the coating chamber is important to obtain the uniform characteristics in long tapes. The idea was applied to fabricate long tapes and a 56 m tape with the end-to-end Ic value of 250 A was realized.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering