J. Phys. IV France
Volume 114, April 2004
Page(s) 223 - 226

J. Phys. IV France
114 (2004) 223
DOI: 10.1051/jp4:2004114048

Strong evidence of field-induced superconductivity and Shubnikov-de Haas oscillation in $\kappa
$ -(BETS) 2FeBr 4

T. Konoike1, H. Fujiwara2, B. Zhang2, H. Kobayashi2, 3, M. Nishimura1, S. Yasuzuka1, K. Enomoto1 and S. Uji1

1  National Institute for Materials Science, Tsukuba, Ibaraki 305-0003, Japan
2  Institute for Molecular Science, Okazaki, Aichi 444-8585, Japan
3  JST-CREST, Kawaguchi, Japan

High field electronic state of the quasi-two dimensional organic superconductor, $\kappa
$-(BETS) 2FeBr 4 was investigated. Under the magnetic field exactly parallel to the conducting layers, zero resistance was observed in the region of about $11 \sim 14$ T at 27 mK. This is the strong evidence of the field induced superconductivity in this salt. In the antiferromagnetic state below 5 T, Shubnikov-de Haas oscillation with a low frequency of 62 T was observed. This new frequency can be ascribed to a small pocket formed by the reconstruction of the Fermi surface due to the antiferromagnetic order. Key words. Organic conductors - Field induced superconductivity - Shubnikov-de Haas oscillation

© EDP Sciences 2004