Long tape processing for coated conductors by multiple-stage CVD method

Toward the industrialization of YBa 2 Cu 3 O 7 x (YBCO) coated conductors for practical applications, metal-organic chemical vapor deposition (MOCVD) has been investigated. We applied multi-stage MOCVD to achieve high-speed production of coated conductor because the increase of the number of depositing stages placed in a line could enlarge deposition area. Using 12-stage CVD, we succeeded in deposition of highly biaxially oriented YBCO layer at tape transfer speed of 50 m/h on the CeO 2 capped ion-beam-assisted-deposition (IBAD) Gd 2 Zr 2 O 7 (GZO) buffered Hastelloy tape, and achieved high critical current density ( c ) exceeding 2 MA cm 2 in a short sample. And it was found that lowering substrate temperature according to YBCO layer growth was effective to increase c . Using this method, high critical current ( c ) of 174 A was achieved by 1 m thick YBCO layer which passed through 12-stage CVD, and 227 A by 1 m thick YBCO layer deposited by 6-stage one. Based on these results, three 200 m-class YBCO layers were deposited by multiple depositions at tape speed of 50 m/h each, using the 12-stage CVD system. A 203 m-long YBCO layer was successfully deposited with end-to-end c of 92.8 A, so that the multiplication of c and length reached 18.8 kA m. These results indicate that a multi-stage CVD technique is useful for a rapid fabrication of long YBCO coated conductor.

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“…3 . The effect of lowering the referential deposition temperature was considered to upkeep the surface temperature of YBCO layer.…”

Section: B High-performance Ybco Layermentioning

confidence: 99%

Rapid Formation of 200 m-long YBCO Coated Conductor by Multi-Stage CVD

Watanabe

Kashima

Suda

et al. 2007

IEEE Trans. Appl. Supercond.

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“…Fabrication of a highly oriented thick superconducting layer is also important for obtaining a high performance in coated conductors. In order to solve this problem, various techniques such as PLD (pulsed laser deposition) [11], MOD (metal-organic deposition) using TFAs (trifluoroacetates) [12] and MOCVD (metal-organic chemical vapour deposition) [13] have been investigated to obtain the superconducting layers. Recently, the long tape processing for both buffer and superconducting layers with good alignment and high crystallinity shows rapid progress, enough to start R&D for the device applications in Japan.…”

Section: Background Of Developments For Re123 Wiresmentioning

confidence: 99%

Highlights of coated conductor development in Japan

Teranishi¹,

Izumi²,

Shiohara³

2006

Supercond. Sci. Technol.

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Coated conductors using RE-Ba-Cu-O (RE: rare earth element) superconductors have been expected to be used in many electric power applications since they have a high critical current density at liquid nitrogen temperature even under high magnetic fields. Many efforts have been made in development of processing for a long coated conductor with high superconducting performance. In Japan, the new five-year national project for development of coated conductor processing was started in FY2003 and was scheduled until the end of FY2007. The expected goals in this project are 500 m long tapes with a high I c value of 300 A cm −1 W −1 at a production rate of 5 m h −1 etc. The progress in recent years is remarkable, such as long tapes over 100 m in length with high I c values of over 100 A cm −1 W −1 . The long tapes have been successfully realized by not only one institution but several. Additionally, a solenoid type magnet and a power cable using YBCO conductors have already been demonstrated as one of the preliminary results for applications. For the future plans of coated conductor applications, the following power devices using coated conductors have been proposed: (1) power cable, (2) transformer, (3) motor, (4) fault current limiter, (5) cryocooler and so on.

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“…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].…”

Section: Introductionmentioning

confidence: 99%

“…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].…”

Section: Introductionmentioning

confidence: 99%