J. Phys. IV France
Volume 114, April 2004
Page(s) 175 - 181

J. Phys. IV France
114 (2004) 175
DOI: 10.1051/jp4:2004114041

Investigation of the field-induced phases in $\lambda
$ -(BETS) 2Fe xGa 1-xCl 4

J.S. Brooks1, S. Uji2, E.S. Choi1, H. Kobayashi3, 4, A. Kobayashi5, H. Tanaka6 and M. Tokumoto6, 4

1  National High Magnetic Field Laboratory and Physics Department, Florida State University, Tallahassee, FL 32310, USA
2  National Institute for Materials Science, Tsukuba, Ibaraki 305-0003, Japan
3  Institute for Molecular Science, Okazaki, Aichi 444-8585, Japan
4  JST-CREST, Kawaguchi, Japan
5  Dept. of Chemistry, University of Tokyo, Bunkyo-ku, Tokyo 113, Japan
6  Nanotechnology Research Institute, AIST, Tsukuba 305-8568, Japan

We investigate the nature of the magnetoresistance in the antiferromagnetic, metallic, and field-induced superconducting ground states of the quasi-two dimensional organic-magnetic conductor $\lambda
$ -BETS 2Fe xGa 1-xCl 4 for several alloy and experimental configurations. These include a consideration of scaling-type behaviour for x = 0.47 where the field is directed in plane along the c-axis. Here we find that both the antiferromagnetic and the superconducting states follow relatively simple scaling laws with magnetic field and temperature respectively over a considerable range of the phase diagram. An investigation of systematic rotation of the magnetic field with respect to both polar and azimuthal directions for x = 0.8 in high magnetic fields is also reported for both the metallic and antiferromagnetic phases. Key words. Organic conductors - field-induced superconductivity - antiferromagnetism.

© EDP Sciences 2004