Electron transport in the granular amorphous carbon films with cobalt nanoparticles

The temperature dependence of electric conductivity was studied in a granular amorphous carbon containing cobalt nanoparticles at an overall cobalt concentration below the percolation threshold. It was established that the electron transport in this structure is determined by the inelastic resonance electron tunneling via localized states, which are situated in the dielectric carbon matrix between isolated conducting metal clusters. The number of the localized states is determined as a function of the cobalt concentration in the composite.