| 학회 | 한국재료학회 |
| 학술대회 | 2016년 가을 (11/16 ~ 11/18, 경주 현대호텔) |
| 권호 | 22권 2호 |
| 발표분야 | H. 한-일 재료공학 워크샵 |
| 제목 | An new iron-based superconducting wire |
| 초록 | Since the discovery of iron-based high temperature superconductors1 which exhibit transition temperatures (Tc) at temperatures (T) ＞ 25 K, tremendous effort has been done for searching novel high-Tc iron-based superconductors. The most characteristic feature of these iron-based superconductors is high superconducting (SC) critical magnetic field (Hc2). The iron-based superconductors have been focused for their potential of applications under high magnetic fields.2 An essential technique for these applications is a fabrication of SC wires with lower costs and simple procedures; i.e. Powder-in-tube (PIT) method. SC wires are reported using AeFe2As2 (122 phase), LnFeAsO (1111 phase), and FeCh (11) phase as a SC core. Ae, Ln, and Ch denote alkali earth, lanthanide, and chalcogenide. Although several research groups have tried to make practical superconducting wire using iron-based SC, practical SC critical current (Jc ＞ 0.1 MAcm-2) has been attained for SC wires using only 122 phase.3,4 SC 122 phase, which is not oxide, may tend to react with moistures in air. It means that more stable superconducting compounds are favourable and required for a superconducting core material in practical superconducting PIT wires. An iron-based SC Sr2VFeAsO3-, which is a mixed anion compound, shows superconducting phase at T ＜ 37 K.5,6 Further, 0Hc2 of Sr2VFeAsO3- are higher than 100 T. Sr2VFeAsO3- is a promising material for SC wire used under high magnetic field. We demonstrate a new iron-based superconducting wire fabricated by PIT method using perovskite-related-type iron-based SC, Sr2VFeAsO3-. Polycrystalline Sr2VFeAsO3- were synthesized via two step solid state reaction. The wires were fabricated using Fe/Ag bimetallic sheath of 6 mm in outer diameter and 3 mm in inner diameter. The sheath was rolled to wire of approximately 1 mm in diameter. They were heated in an evacuated quartz tube at 900 C for eight different sintering times as 1 h, 2 h, 4 h, 8 h, 16 h, 32 h, 64 h and 128 h. In this workshop, we will report the detail for fabrication of wires and their superconducting properties. |
| 저자 | Suguru IWASAKI, Masanori MATOBA, Yoichi KAMIHARA |
| 소속 | Keio Univ. |
| 키워드 | Sr2VFeAsO3; iron-based superconductors; Powder-in-tube (PIT); Perovskite-related |
