OHMIC RESISTIVITY AND NONLINEAR TRANSPORT OF CHARGE DENSITY WAVES IN BLUE BRONZES K0.3MoO3

Ohmic resistivity and nonlinear transport properties of sliding charge density wave (CDW) conduction in blue bronze K0.3MoO3 were measured. It is found that at about 183 K the sample undergoes a metal-to-semiconductor transition, i.e. Peierls transition. In semiconducting CDW state, the estimated activation energies eg in the temperature ranges of 77–135 and 150–180 K are, respectively, about 0.033 and 0.051 eV by the measurements of ohmic resistivity, where the field is below the depinning field VT of CDW motion. Above VT, the analytic form of nonlinear current of sliding CDW in a moderate current range fits the power law relation, i.e. ICDW∝(V/VT−1)α; the exponent a is not a constant, but relies on temperatures. In high field range, the analytic form of nonlinear current of the CDW motion deviates from the power law relation, but it can be described by the microscopic model including the internal degrees of freedom proposed by Sneddon et al., i.e. ICDW=σnE+CE1/2, with σn being the conductivity of normal...