Novel conductive radical cation salts based on methylenediselenotetraselenafulvalene (MDSe-TSF): A sign of superconductivity in κ-(MDSe-TSF)2Br below 4 K

Mie Kodani, Ayumi Takamori, Kazuo Takimiya, Yoshio Aso, Tetsuo Otsubo

Research output: Contribution to journalArticlepeer-review

23 Citations (Scopus)

Abstract

Seven conductive radical cation salts based on MDSe-TSF (methylenediselenotetraselenafulvalene) have been synthesized by electrocrystallization in the presence of Cl-, Br-, I3-, I2Br-, PF6-, ClO4-, and Cu(NCS)2- counter anions. The crystal appearances of these salts fairly depend on the anions employed. X-ray crystallographic analyses have revealed that the PF6 and ClO4 salts in the shape of brown thin plates adopt the θ-type structures characterized by the herringbone arrangement of donor stacks, whereas the Cl and Br salts in the shape of black thick plates favor the κ-type structures with the orthogonal arrangement of donor dimers. Regardless of different crystal appearances or crystal packing patterns, all these salts show high conductivity (> 102 S cm-1) at room temperature and retain metallic properties down to 4.2 K. Of them, the Br salt shows a weak but distinct diamagnetic shielding signal below 4 K in the dc magnetization measurement under zero-field-cooled (ZFC) condition, suggesting a sign of superconductivity. The band calculations of both PF6 and Br salts demonstrate closed Fermi surfaces indicative of two-dimensional molecular conductors.

Original languageEnglish
Pages (from-to)582-589
Number of pages8
JournalJournal of Solid State Chemistry
Volume168
Issue number2
DOIs
Publication statusPublished - 2002 Nov 1
Externally publishedYes

Keywords

  • Magnetic susceptibility
  • Organic superconductor
  • Radical cation salt
  • Selenium-containing electron donor
  • X-ray structure analysis

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Condensed Matter Physics
  • Physical and Theoretical Chemistry
  • Inorganic Chemistry
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Novel conductive radical cation salts based on methylenediselenotetraselenafulvalene (MDSe-TSF): A sign of superconductivity in κ-(MDSe-TSF)<sub>2</sub>Br below 4 K'. Together they form a unique fingerprint.

Cite this