J. Phys. IV France
Volume 114, April 2004
Page(s) 391 - 392

J. Phys. IV France
114 (2004) 391
DOI: 10.1051/jp4:2004114093

Phase diagram of magnetic-field-induced superconductor $\lambda $-(BETS) 2FeCl 4-xBr x

S. Uji1, 1, S. Yasuzuka1, H. Tanaka2, 3, M. Tokumoto2, 3, B. Zhang4, H. Kobayashi4, 3, E.S. Choi5, D. Graf5 and J.S. Brooks5

1  National Institute for Materials Science, Tsukuba, Ibaraki 305-0003, Japan
2  Nanotechnology Research Institute, AIST, Tsukuba 305-8568, Japan
3  JST-CREST, Kawaguchi, Japan
4  Institute for Molecular Science, Okazaki, Aichi 444-8585, Japan
5  National High Magnetic Field Laboratory, FSU, Tallahassee, FL 32310, USA

Resistance measurements of $\lambda $ -(BETS) 2FeCl 4-xBr x (x=0.7) have been performed to investigate the high magnetic field electronic state. When the magnetic field is applied exactly parallel to the c axis (in the conducting layers), superconducting phase is stabilized above 27 T for T < 2K after the antiferromagnetic insulating (AFI) phase is removed. The critical temperature Tc has a maximum at about 32 T, which is in good agreement with the case for x=0. However, the AFI phase is more stabilized for x=0.7 than for x=0. Key words. BETS system - superconductivity - $\pi d$ interaction.

© EDP Sciences 2004