Random media with temperature controlled connectivity

(Received 3 March 1992, accepted 12 March 1992)

Abstract
We show that the electrical resistance of a percolating medium made of a polymer filled with conductive particles may undergo a steep increase over a narrow temperature range above room temperature. We demonstrate that a likely mechanism for the effect is the loss of interparticle electrical contact inducing a weakening of the connectivity of the medium as temperature is increased.