Temperature dependence of the second threshold field for rubidium blue bronze Rb0.3MoO3

We have investigated the threshold properties of Rubidium blue bronze Rb0.3MoO3 under high dc electric field in a large temperature range 20–150 K. The second threshold fields have been observed at temperature up to 102.4 K, and have quasi-linear relationships with temperatures 20–45 K and 55–100 K, respectively. A novel crossover platform has been found firstly in the temperature dependence of the second threshold field ET2 at about 45–55 K. The results indicate that the dynamical behavior of the second threshold effects may originate from different mechanisms. We suggest that the highly conducting state at 20–45 K and 55–100 K result from the undamped sliding motion of rigid CDW and current inhomogeneity, respectively.