Dielectric response of the charge-density wave inK0.3MoO3

Abstract

We have characterized the dielectric relaxation of the charge-density wave (CDW) in ${\mathrm{K}}_{0.3}$ ${\mathrm{MoO}}_3$ at temperatures between 60 and 101 K through measurement of the complex conductivity between 5 Hz and 13 MHz. The dielectric response is described well by a general expression which allows for a distribution of relaxation times which is not symmetric about the mean relaxation time. Between 60 and 101 K, relaxation times decrease in a manner characteristic of Arrhenius behavior. The dielectric response of the CDW for dc biases below the threshold field for nonlinear conductivity is suggestive of critical behavior. Above the threshold field, the ac conductivity shows structure at frequencies equal to the "washboard frequency" of the sliding CDW.