J. Phys. IV France
Volume 114, April 2004
Page(s) 269 - 272

J. Phys. IV France
114 (2004) 269
DOI: 10.1051/jp4:2004114056

Dynamical charge disproportionation in metallic state in $\theta$-(BEDT-TTF) 2RbZn(SCN) 4

T. Takahashi1, 1, R. Chiba1, K. Hiraki1, H.M. Yamamoto2 and T. Nakamura3

1  Department of Physics, Gakushuin University, Mejiro, Toshima-ku, Tokyo 171-8588, Japan
2  The Institute of Physical and Chemical Research, 2-1 Hirosawa, 351-0198 Wakou, Japan
3  Institute for Molecular Science, Myodaiji, 444-8585 Okazaki, Japan

Results of 13C-NMR experiments on charge ordering in non-dimerized BEDT-TTF salts are discussed. It has been experimentally confirmed in $\theta$-(ET) 2RbZn(SCN) 4 that charge disproportionation already develops well above the metal-insulator transition temperature while no long-range charge order is stabilized. Dynamics of the charge fluctuations has been determined in this salt and compared with the situations in $\alpha $-(ET) 2I 3. This result seems to require a serious reconsideration of the transport properties in the metallic state. Key words. 13C-NMR, Charge disproportination.

© EDP Sciences 2004