Development of Simple Manufacturing Process for Fe-based Superconducting Wire Material

2009.06.09

National Institute for Materials Science
Japan Science and Technology Agency

The National Institute for Materials Science and the Japan Science and Technology Agency succeeded in the development of a simple manufacturing process for superconducting wire material using an Fe-based superconductor. This achievement was the result of research by a team led by Dr. Yoshihiko Takano, Group Leader of the Nano Frontier Materials Group in NIMS Superconducting Materials Center.

Abstract

  1. The National Institute for Materials Science (NIMS; President: Prof. Teruo Kishi) and the Japan Science and Technology Agency (JST; President: Koichi Kitazawa) succeeded in the development of a simple manufacturing process for superconducting wire material using an Fe-based superconductor. This achievement was the result of research by a team led by Dr. Yoshihiko Takano, Group Leader of the Nano Frontier Materials Group in NIMS Superconducting Materials Center (Managing Director: Hiroaki Kumakura).
  2. At the beginning of 2008, a group under Prof. Hideo Hosono of Tokyo Institute of Technology discovered an LaFeAsO system Fe-based superconductor. This discovery led to an “Fe-based superconductor boom,” and a succession of new superconductors based on similar compounds were discovered, including SrFe2As2, LiFeAs, and Fe(Se,Te) systems, among others. For application of these Fe-based superconductors, manufacture of prototype superconducting wire materials is required. Because the superconducting current which passes through a superconducting wire can carry electricity with zero loss, these materials are expected to play a key role in solving environmental and energy related problems. Recently, groups in China manufactured prototype wire materials using LaFeAsO system and SrFe2As2 system superconductors, but in both cases, these materials failed to pass a superconducting current in power-on tests.
  3. The Fe-based superconductor which the NIMS-JST group used in this research was Fe(Se,Te), which has the simplest crystal structure. Iron, which is the main component in Fe-based superconductors, is a material that exists in abundance and is widely used at present. Taking advantage of its features, this group developed a simple manufacturing method for superconducting wiring materials in which iron is used in the sheath material of the superconducting wire, and at the same time, the sheath material also plays a dual role as a superconducting substance. The trial manufacture of this wire material using an FeSe system was the first in the world. This work was also the world’s first example in which the critical supercurrent was successfully passed with a wire using an Fe-based superconductor.
  4. With the process discovered in this research, production of multi-core wires and long wires is simple, and application to superconducting magnets using these materials is considered feasible. Improved performance is also expected by using hot-press technique in which material is heat-treated during rolling, and others. From the practical viewpoint, because the manufacturing process is simple, a larger number of researchers are expected to participate in research and development in the future, giving impetus to applied research.
  5. This research achievement was obtained as part of work on the research topic “Elucidation of the Mechanism of FeSe Superconductors and Search for New Materials” (Research Director: Yoshihiko Takano) of the JST’s Basic Research Program in the research field “Basic Technologies for High Temperature Superconducting by New Materials” (Research Supervisor: Hidetoshi Fukuyama, Professor, Tokyo University of Science, Faculty of Science).