Journal of Solid State Chemistry
Volume 67, Issue 1, March 1987, Pages 122-130
doi:10.1016/0022-4596(87)90347-1 Copyright © 1987 Published by Elsevier Science (USA).

Electronic properties of sodium-C222-sodide

John Papaioannou*, Stephan Jaenicke and James L. DyeCorresponding Author Contact Information

Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA

Received 26 November 1984;  revised 28 April 1986.  Available online 11 December 2003.


The electrical conductivity of both polycrystalline and single-crystal Na+C222 · Na was measured as a function of temperature from 220 to 280 K and the dielectric constant of polycrystalline samples was studied as a function of frequency from 1 kHz to 10 MHz at several temperatures. The results show both electronic and ionic conductivity for single crystals but the ionic contribution is suppressed in polycrystalline samples. The activation energies for ionic and electronic transport are 1.6 ± 0.2 eV and 1.2 ± 0.1 eV, respectively. After being subjected to a dc potential of>2.0 V for a period of time, single crystals had an open circuit voltage that decayed only slowly with time, showing that the system behaves as an electrochemical cell. When the potential was <2.0 V, the effect was absent. The results are in agreement with ionic conduction by Na+ superimposed on a background of electronic conduction.

Corresponding Author Contact InformationCorresponding author. Author to whom correspondence should be addressed.

* Current address: Department of Chemistry, University of Athens, Athens, Greece.

Current address: Fritz-Haber-Institut der Max Planck Gesellschaft, Berlin, West Germany.