Synthesis of exotic high-tempeature superconductors via the co-intercalation of metal and organic molecules

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K13512
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics II
• Research Institution: Tohoku University
• Principal Investigator: Koike Yoji 東北大学, 工学研究科, 教授 (70134038)
• Co-Investigator(Renkei-kenkyūsha): NOJI Takashi 東北大学, 大学院工学研究科, 助教 (50180740) ; KAWAMATA Takayuki 東北大学, 大学院工学研究科, 助教 (00431601)
• Research Collaborator: HATAKEDA Takehiro 東北大学, 大学院工学研究科 ; HOSONO Shohei 東北大学, 大学院工学研究科 ; SATO Kazuki 東北大学, 大学院工学研究科 ; HOSAKA Shunsuke 東北大学, 大学院工学研究科 ; NAKAMURA Shin-ichiro 東北大学, 大学院工学研究科
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: 高温超伝導 / インターカレーション / アルカリ金属 / 有機分子 / 鉄系超伝導体 / 遷移金属カルコゲナイド / 電荷密度波

Outline of Final Research Achievements

We have succeeded in the synthesis of new superconductors of Ax(C6H16N2)yFe2-zSe2 and Ax(C8H11N)yFe1-zSe (A = Li, Na) with the superconducting transition temperature Tc = 38 - 44 K via the co-intercalation of alkali metal and hexamethylendiamine (HMDA) or 2-phenethylamine into FeSe. These Tc values are similar to those of single-layer films of FeSe. Accordingly, we have concluded that unfortunately no further enhancement of Tc is expected through any further expansion of the interlayer spacing between FeSe layers.
We have also succeeded in the synthesis of new superconductors of Lix(C2H8N2)yMSe2 and Lix(C6H16N2)yMSe2 (M = Ti, Mo) with Tc = 2.4 - 6.0 K via the co-intercalation of Li and ethylendiamine (EDA) or HMDA into MSe2. Moreover, we have succeeded in the synthesis of a new superconductor of (C2H8N2)yTa2PdSe6 with Tc = 4.5 K via the intercalation of EDA into Ta2PdSe6.

Free Research Field

低温電子物性、超伝導