We have studied the angular dependence of magnetoresistance and Hall effect of the CDW organic conductor, HMTSF-TCNQ in order to see whether a magnetic-field-induced phase exists in the charge density wave (CDW) system, similarly to the magnetic-field-induced SDW phases in (TMTSF)2X. The anomaly in magnetoresistance was observed only around the pressure where the CDW is almost suppressed, i.e. around 0.8-1.1 GPa, but neither at low pressures (0 and 0.5 GPa) nor at high pressure above 2 GPa. This behavior is quite similar to that of (TMTSF)2X. At 1.1 GPa anomalies were found at fields of 0.2 T and 10 T. We speculate that at 1.1 GPa the field-induced phase is located between 0.2 T and 10 T, where 1D Fermi surface sheet and 2D Fermi-surface pocket are present. The Rxy shows plateau structure and Rxx was very small in the same region, suggestive of quantum Hall effect.
- Charge density wave (CDW)