Nomadic polarization in doped poly(o-methoxyaniline) films

The AC conductivity of poly(o-methoxyaniline) —POMA films with various doping levels were studied in the temperature range of 4.2 to 298 K. In the low frequency regime the conductivity is frequency-independent, but above a critical angular frequency ωc it obeys an equation of the form σ(ω) α ωs. Both the DC conductivity σ0 and the critical frequency increase with temperature, whereas the exponential factor s is temperature-independent. Since the conduction of doped POMA is strongly dependent on the electronic mobility along the molecule backbone, a nomadic polarization model of quasi-one-dimensional solids was used to fit the experimental results. Values for the bulk mobility, the carrier density and the transition rate of the intermolecular charge transfer were estimated.