METAL-INSULATOR-TRANSITION IN AN IRREGULAR STRUCTURE OF COUPLED METALLIC CHAINS

A model of the random network of coupled metallic wires is suggested t o describe transport properties of highly conducting fibril-form polym ers. The suppression of closed paths in the model enables us to study exactly the transition from the dielectric to the conductive state. Th e critical concentration of the interwire crosslinks determining the t ransition depends on the localization length of a single wire and on t he interwire coupling. The temperature dependence of the network condu ctivity near the transition is discussed.