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 omega(c) it obeys an equation of the form sigma(omega) proportional to omega(s). Both the sigma(0) conductivity oo 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.