Author/Authors :
Kobayashi، نويسنده , , H. and Tanaka، نويسنده , , H. and Fujiwara، نويسنده , , H. and Tamura، نويسنده , , I. and Gritsenko، نويسنده , , V. and Otsuka، نويسنده , , T. and Fujiwara، نويسنده , , E. and Kobayashi، نويسنده , , A. and Tokumoto، نويسنده , , M. and Cassoux، نويسنده , , P.، نويسنده ,
Abstract :
The physical properties of BETS (=bis(ethylenedithio)tetraselenafulvalene) conductors with tetrahalide magnetic anions and related systems were investigated. We have recently succeeded to find the superconducting transition of the crystal of κ-type TlCl4− salt coated with epoxy resin (Tc(onset)=2.5 K). The specific heat measurements on the antiferromagnetic organic superconductor, κ-(BETS)2FeCl4 was performed down to 60 mK, which gave sharp peak at 0.45 K (TN). The peak trails a tail at T>TN, suggesting low-dimensionality of the spin system. Resistivity measurements under magnetic field of λ-(BETS)2FexGa1−xCl4 (x≈0.4) exhibiting superconductor-to-insulating (SC–I) transition, I–SC phase transition was observed around 4 T at T<3 K. The “low-field superconducting region” between metallic and insulating phases around zero magnetic field is connected with the “high-field superconducting region”.
Keywords :
Organic superconductor , Antiferromagnetic transition , Magnetic superconductor , Magnetic molecular conductor , ?–d Interaction
