J. Phys. IV France 12 (2002) Pr9-317
DOI: 10.1051/jp4:20020425

Electronic properties of (DMTSA)BF ₄ at ambient pressure

M. Nagasawa¹, K. Kawabata², T. Sambongi³, P. Monceau⁴ and T. Otsubo<sup>5

1</sup>  Tokyo Denki University, 2-2 Nishikicyo, Kanda, Chiyoda, Tokyo 101-8457, Japan
²  Hokkaido University, Sapporo 060-0810, Japan
³  Hokkaido Information University, Ebetsu 069-8585, Japan
⁴  CRTBT, CNRS, Grenoble, France
⁵  Hiroshima University, Higasihiroshima, Japan

Abstract
Organic conductor (DMTSA)BF ₄ [DMTSA: 2,3dimethyl-tetra-sleno-antracene] is a compound composed of an electron donor DMTSA and a monovalent acceptor BF ₄^-. In the salt, the electronic system is expected to be the Mott-Hubbard insulator. However, its conductivity at room temperature is 200~400 cm ^-1 and behaves metallic above 2OOK. At ambient pressure, we found anomalies both in the DC conductivity components and in the permittivity at ~80K, similar to those in (TMTTF) ₂X associated with charge ordering at ~100K. In the insulating state under low pressure, we found that the sample shows non-linear conduction with threshold. We discuss the possible origin of the anomalies and the apparent similarity with the non-linear electric conduction by the density wave sliding.

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