High quality thin films of iron-based superconductors and the fabrication technology of superconducting junctions

2014 Fiscal Year Final Research Report

• Project/Area Number: 24246007
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Applied materials science/Crystal engineering
• Research Institution: Nagoya University
• Principal Investigator: HIROSHI Ikuta 名古屋大学, 工学(系)研究科(研究院), 教授 (30231129)
• Co-Investigator(Kenkyū-buntansha): TANAKA Yukio 名古屋大学, 大学院工学研究科, 教授 (40212039) ; TABUCHI Masao 名古屋大学, シンクロトロン光研究センター, 特任教授 (90222124)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 超伝導材料 / 分子線エピタキシー法 / 鉄系超伝導体 / 低温物性 / エピタキシャル成長

Outline of Final Research Achievements

The recently discovered iron-based superconductors are attracting the attention of many researchers because they are forming a new family of high temperature superconductors. In this project, we have studied thin film growth of these materials and the fabrication of several superconducting junctions. We have improved significantly the film quality of NdFeAs(O,F), which has the highest transition temperature (Tc) among the iron-based superconductors discovered so far. For BaFe2(As,P)2, which has a somewhat lower Tc but very high crystalline quality, we succeeded in the growth of thin films for the whole composition range. Thin films of CaFe2As2-based materials were also grown for the first time. Using these thin films, we have fabricated grain boundary junctions, and studied the junction properties. A method to form a smooth CaF2 barrier for the fabrication of planar type junctions was developed, and we also studied the growth of stacked hetero-junctions based on BaFe2(As,P)2.

Free Research Field

超伝導工学・電子物性