Long aging time thermal degradation of the ac conductivity and complex permittivity of conducting polypyrrole
arXiv:1105.2110 · doi:10.1016/j.synthmet.2011.04.020
Abstract
The modification of the ac conductivity and the complex permittivity of conducting polypyrrole was monitored throughout a two years thermal aging at 343K. Reduction of the cross-over frequency is correlated with the degradation of dc-conductivity, while the ac conductivity region corresponding to the so-called 'universal' dielectric relaxation remains practically invariant during the first year of ageing, which implies a collective co-operativity among multiple degradation processes that yield a practically time-independent effective disordered environment. A broad dielectric loss peak recorded in fresh specimens splits into two distinct relaxations for intermediate stages of the annealing process. The ageing-time evolution of the dc component and the relaxations are qualitatively analysed and time constants are determined.
arXiv commentSynth. metals (2011) in print