J. Phys. IV France
Volume 114, April 2004
Page(s) 105 - 103

J. Phys. IV France
114 (2004) 105
DOI: 10.1051/jp4:2004114020

Spin and anion dynamics on (TMTSF) 2FSO 3, studied by NMR

K. Hiraki1, 1, H. Kang2, T. Nemoto1, H. Satsukawa1, T. Takahashi1, Y.J. Jo2, W. Kang2, 2 and O.H. Chung3

1  Department of Physics, Gakushuin University, Mejiro, Tokyo 171-8588, Japan
2  Department of Physics, Ewha University, Seoul 120-750, South Korea
3  Department of Physics, Sunchon University, Seoul 120-750, South Korea

In order to characterise the electronic properties in sub-phases of (TMTSF) 2FSO 3 under pressure, 77Se, and 19F NMR Knight shift ( K) and relaxation rate (1/ T1) measurements were performed at ambient and 0.82 GPa pressure. The insulating phase below the metal-insulator transition (MIT) at 89 K at ambient pressure (AP) was confirmed as a nonmagnetic state with a gap of $\Delta $/ $k_{B}\sim 420$ K. This MIT is strongly coupled with anion ordering. The MIT temperature decreases under pressure, and many electronic anomalies (or transitions) have been observed from transport measurements. The reduction of density of states in the metallic state by applying pressure was confirmed by the analysis of K and Korringa constant (1/ T1T). A nonmagnetic insulating transition corresponding to the MIT at AP at 89 K, was observed at $\sim
$ 45 K at 0.82 GPa. A spin (charge) gap in the insulating state at 0.82 GPa is smaller ( $\Delta $/ $k_{B}\sim 90$ K) than that at AP. Key words. metal insulator transition - NMR

© EDP Sciences 2004