In this work, the electrical properties of carbon– nickel films annealed at different temperatures (573, 773, 1073 and 1273 K) in the temperature range 15–300 K were investigated. The films were grown by radio frequency magnetron co-sputtering on quartz substrates at room temperature. The multiphonon hopping conduction mechanism is found to dominate the electrical transport in the temperature range 150–300 K. It can be seen that the roomtemperature hopping rate (CRT) at 773 K has maximum value of 56.8 9 105 s-1. Our results of conductivity measurements at high temperature are in good agreement with strong carrier–lattice coupling model; on the other hand, the conductivity in the range 15–50 K is well described in terms of variable-range hopping (VRH) conduction mechanism. The localized state density around Fermi level N(EF) and the average hopping energy Whop at low temperature for the films annealed at 773 K have maximum value of 2.23 9 1023 (cm-3 eV-1) and minimum value of 9.74 9 10-4 eV, respectively.
