Metallic phase in potassium fulleride KxC70: Electrical, magnetic, and structural properties of K4C70

Toshifumi Hara, Mototada Kobayashi, Yuichi Akahama, Haruki Kawamura, Mayumi Kosaka, Katsumi Tanigaki

Research output: Contribution to journalArticlepeer-review


The metallic phase in potassium fullerides KxC70 was researched using electrical resistivity measurements in the case of film samples and magnetic susceptibility measurements in the case of powder samples. The K concentration dependence of the electrical resistivity of the K xC70 film at 423 K showed two minima: namely, 1.0×10-1 and 6.1×10-3 Ω cm at x = 1.1 and 4.1, respectively. The temperature dependence of the resistivity of the K4C70 film showed a disordered-metallic behavior. Superconducting quantum interference device (SQUID) measurements for K 4C70 powder revealed a temperature-independent magnetic susceptibility contribution of 3.47×10-4 emu/mol. This contribution was attributed to Pauli paramagnetism, and it was also observed in electron spin resonance (ESR) measurements. Futhermore, ESR spectra for K 4C70 powder showed that the linewidth broadened with increasing temperature. It was clearly established that K4C 70 is a metallic phase in KxC70. The crystal structure of K4C70 was found to be simple tetragonal with a = 1.266 nm and c = 1.098 nm. No superconductivity was observed in K4C70 above 2 K.

Original languageEnglish
Article number045401
Pages (from-to)454011-454015
Number of pages5
JournalPhysical Review B - Condensed Matter and Materials Physics
Issue number4
Publication statusPublished - 2003 Jul 1
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics


Dive into the research topics of 'Metallic phase in potassium fulleride KxC70: Electrical, magnetic, and structural properties of K4C70'. Together they form a unique fingerprint.

Cite this