Synthesis and post-annealing effects of alkaline-metal-ethylenediamine- intercalated superconductors Ax(C2H8N 2)yFe2-zSe2 (A = Li, Na) with Tc = 45 K

Takashi Noji, Takehiro Hatakeda, Shohei Hosono, Takayuki Kawamata, Masatsune Kato, Yoji Koike

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55 Citations (Scopus)


New iron-based intercalation superconductors Ax(C 2H8N2)yFe2- zSe2 (A = Li, Na) with Tc = 45 K have successfully been synthesized via intercalation of dissolved alkaline metal in ethylenediamine. The c-axis lengths of Ax(C2H 8N2)yFe2-zSe2 (A = Li, Na) are 20.74(7) Å and 21.9(1) Å, respectively, and are about 50% larger than that of KxFe2Se2, indicating that not only alkaline metal but also ethylenediamine is intercalated between the Se-Se layers of FeSe. It seems that the high-Tc of Ax(C2H8N2)yFe 2-zSe2 (A = Li, Na) is caused by the possible two-dimensional electronic structure due to the large c-axis length. Through the post-annealing in an evacuated glass tube, it has been found that Tc decreases with increasing post-annealing temperature and that deintercalation of EDA from the as-intercalated sample takes place at low temperatures below 250 °C.

Original languageEnglish
Pages (from-to)8-11
Number of pages4
JournalPhysica C: Superconductivity and its applications
Publication statusPublished - 2014 Sep 15


  • Alkaline metal
  • Etylenediamine
  • FeSe
  • Intercalation
  • Superconductivity

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering

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