J. Phys. IV France
Volume 114, April 2004
Page(s) 467 - 470

J. Phys. IV France
114 (2004) 467
DOI: 10.1051/jp4:2004114109

Conductivity and magnetism by band filling control of organic conductors

H. Mori1, 2, 1, M. Suto1, 3, H. Suzuki1, Y. Nishio3 and K. Kajita3

1  The Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
3  Department of Physics, Toho University, Funabashi, Chiba 274-8510, Japan

Recently the systematic band-filling control has been successfully carried out in organic conductors. The filling control to the various ground state was investigated by doping to the antiferromagnetic insulator for $\lambda $-ET 2(MCl 4)1-x(M'Cl 4)x, the non-magnetic insulator, $\delta
$ '-ET 2(MCl 4)1-x(M'Cl 4)x, the charge ordered conductor, $\alpha $-ET 3(M'Cl 4)1-x(MCl 4)x(TCE), and the band insulator $\beta $'-ET 3(M'Cl 4)2-x(MCl 4)x [M = Ga, Fe, M' = Co, Zn], respectively. he most drastic change was observed for $\beta $'-ET 3(M'Cl 4)2-x(MCl 4)x: the semiconducting behavior transforms to the metallic one from x = 0, 0.66, to 0.58. Moreover, by applying the pressure for x = 0.62, the metallic behavior was observed down to 4 K. On the other hand, the electronic state of the band-filled conductor with magnetic anions is also attractive. The ferromagnetic interaction through the doped carriers was observed for $\beta $ '-ET 3(CoCl 4)2-x(FeCl 4)x. Key words. Band filling - ET salts - transport and magnetic properties.

© EDP Sciences 2004