J. Phys. IV France
Volume 114, April 2004
Page(s) 157 - 158

J. Phys. IV France
114 (2004) 157
DOI: 10.1051/jp4:2004114038

Pressure-induced Fermi surface change in quasi-one-dimensional conductor ${\beta ''}$-(ET)(TCNQ)

S. Yasuzuka1, 2, D. Graf3, E.S. Choi3, J.S. Brooks3, T. Terashima2, T. Konoike2, K. Enomoto2, M. Nishimura2, H.M. Yamamoto4, R. Kato4 and S. Uji2

1  Division of Physics, Hokkaido University, Sapporo 060-0810, Japan
2  National Institute for Materials Science, Tsukuba 305-0003, Japan
3  Florida State University/National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA
4  Condensed Molecular Materials Lab., RIKEN, JST-CREST, Saitama 351-0198, Japan

We report results of the magnetoresistance measurements of ${\beta ''}$-(ET)(TCNQ) under a pressure of 7 kbar. The resistance is found to show a large peak at 37 K suggesting some phase transition. When the field applied perpendicular to the conducting layers, a resistance hump appears at 12 K. The Shubnikov-de Haas oscillation with a high frequency of 4183 T is observed below 1 K, whose cross sectional area corresponds to about 30% of the first Brillouin zone. The effective mass is estimated to be 4.5 m0. These results, which are quite different from the ambient e data, show a drastic change of the electronic state under 7 kbar.

Key words. ${\beta ''}$-(ET)(TCNQ), Fermi surface, magnetic field, pressure, magnetoresistance.

© EDP Sciences 2004