Speaker
Description
Author information
* Makoto Inagaki1, Genki Honda1, Tatsuhiko Yoshihara1, Tomohiro Ito1, Tatsuoki Nagaishi1, Shinichi Kobayashi1, Kiyoshi Kanie2, Tatsunori Okada3,4, Satoshi Awaji3
Advanced Superconductor Department‚ Frontier Power System R&D Center, Sumitomo Electric Industries, Ltd., 1-1-3, Shimaya, Konohana-ku, Osaka, Osaka, 552-0024, Japan1
International Center for Synchrotron Radiation Innovation Smart, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan 2
High Field Laboratory for Superconducting Materials, Institute for Materials Research, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan3
Department of Materials Science and Engineering, Kyushu Institute of Technology
1-1 Sensui-cho, Tobata-ku, Kitakyushu, Fukuoka 804-8550, Japan4
Abstract body
High field magnets for MRI, NMR, and especially for fusion reactors have a strong demand for low-cost REBCO tape. Sumitomo Electric Industries, Ltd. has been developing REBCO tape fabrication by Fluorine-free MOD (FF-MOD) method, which is an environment-friendly process for REBCO fabrication. Additionally, FF-MOD is a cost-effective process since inexpensive and easily prepared solutions can be used, there is nearly 100% material yield, and no special energy source is required except for a conventional tube furnace. It used to be hard to include artificial pinning centers (APCs) in the process needed for high field applications. However, we recently reported successful fabrication of FF-MOD films with BaHfO3 (BHO) nanoparticles as APCs by applying a poly-crystallization sintering process[1]. We developed BHO nanoparticles with a minimum diameter of 2 nm by utilizing the solvothermal method with some modifications[2]. By adopting those techniques, we have succeeded in fabricating epitaxial REBCO films with BHO on IBAD-MgO-based Ni-alloy tape by FF-MOD method. When the film thickness is thinner than 350 nm, the in-plane texture of REBCO improves with film thickness and converges to 2-3 degrees [3]. The critical current of the thin films is dependent on the texture of the buffer layer. On the other hand, as the film thickness increases, the in-plane texture of thick film becomes constant regardless of the film thickness. Therefore, the contribution of the buffer layer texture to thick film becomes much less, resulting in a high Ic. As results, the Ic increases linearly with increasing REBCO thickness and 164 A/4mm-width at 20 K, 20 T (B||c) was achieved with the film of 3.1μm thickness. Furthermore, REBCO films grown by the FF-MOD method show very high Ic even at 77 K and self field, which exceeds 460 A/4mm-width. Furthermore, REBCO tapes longer than 300 m without defects related to the FF-MOD process were successfully fabricated recently.
References
[1] T. Yoshihara et al., IEEE Trans. Appl. Supercond., 33 (2023) 6600205.
[2] N. Chamorro et al., RSC Adv., 10 (2020) 28872.
[3] G. Honda et al., IEEE Trans. Appl. Supercond. (2024) submitted.
| Session | Conductor Manufacturing |
|---|
