High Pressure Conductivity Study of Template Synthesized Polypyrrole: Observation of a Crossover from Three to One Dimensional Variable Range Hopping.

We have studied thin films composed of thin and thick wall template synthesized polypyrrole microtubules. We observe a crossover from three to one dimensional variable range hopping in our samples at low temperatutes. Our results clearly indicate that the geometry of the microtubules has an influence on the conductivity. The transition temperature from 3 to 1 dimensional variable range hopping shifts to lower temperatures when high pressure is applied. The results are discussed on the basis of the geometry of the microtubules.