We report on two series of separate magnetoresistance measurements (20T/10mK and 23T/500mK) on (TMTSF)2ClO4 single crystals with magnetic field along the c*-axis. Two distinct rapid oscillations with the same frequency but phases different by π separate the main field-induced spin-density-wave phase into subphases. An additional anomaly is evidenced at low temperature as the field is swept through a very narrow interval centered around 17.5T. We address the possibility of a crossover line in the temperature vs field phase diagram which would connect the first order transition line discovered by McKernan et al.
- Organic superconductors
- Quantum Hall effect