Electrical Properties of a Periodic Porous Carbon Replica of Opal

Abstract

The electrical conductivity and magnetoconductance of pyrolized porous phenolic resin opal replicas have been studied as a function of their heat treatment temperature (HTT) up to 2380°C. Porous graphite can be formed by pyrolizing the phenolic resin opal replica. In the case of replicas with a low HTT, a crossover from Mott variable range hopping (VRH) to Efros and Shklovskii VRH upon decreasing the temperature has been experimentally observed. For those with a high HTT, the electrical properties are consistent with those of pyrolytic graphite. The occurrence of positive magnetoconductance indicates the existence of quantum effect at low temperatures.