ELECTRICAL-PROPERTIES OF THE POLYMER COMPOSITE POLYSTYRENE IRON PARTICLES/

The control of electrical conductivity of a polystyrene matrix (PS) ca n be made by the inclusion of conducting particles. We observe, in sev eral systems, a percolation threshold: dependent on different paramete rs, as the temperature and the type of particles. In this work, we pre sent the results of d.c. conductivity (sigma(dc)), Of the PS system do ped with iron particles, as a function of concentration, temperature a nd electrical field. The measurements are repeated several times, in a n attempt to find ageing effects of the material due to temperature. T he data show the nonlinearity of the current with electric field. A ph ysical model is presented to explain the results.