Magnetic property of the low temperature phase of a-(bedt-´ftf)2kh9(scn)4

Summary form only given. The mysterious low temperature phase of the organic conductor, /spl alpha/-(BEDT-TTF)/sub 2/KHg(SCN)/sub 4/, has been interested. Anisotropic static magnetic susceptibility suggesting an antiferromagnefism has been observed in this phase. /sup 1/H-NMR and /spl mu/SR measurements, however, failed to observe any localized moment. While extensive studies have been carried out, the nature of the low temperature electronic state is still an open question. In this report, we carried out EPR measurement to determined the absolute value of the spin susceptibility. The EPR intensity decreased gradually as temperature decreased from room temperature to 10 K, which agrees the static susceptibility. Below 10 K the EPR intensity decreased suddenly for all directions of the applied field. The disappearance of the paramagnetic signal is qualitatively consistent with a magnetic ordering. The residual signal below 10 K was found to split into three which has different angular dependence. There are two possible interpretations of the splitting; the crystal used here may be twin or triplet or the electron spins may be localized at the three crystallographically independent BEDT-TTF molecules of the /spl alpha/ type structure.