Transport properties including conductivity and magnetoconductance have been measured for amorphous nickel-silicon films. This study focuses on metallic amorphous a-Ni x Si 1−x films, located just above the metal-insulator transition (MIT). Using various techniques, the MIT was identified. Electron-electron interactions dominated the conductivity, where σ ≈ σ (0) + CT 0.55. Strong spin-orbit scattering was important in the weak-localization contribution to the magnetoconductance data for the metallic films. The inelastic scattering time was extracted from the magnetoconductance data. The low-temperature magnetoconductance data versus Ni content x exhibited a negative maximum just above the critical concentration x c , suggesting another technique for identifying the MIT.

The electronic conductivity has been measured in homogeneous, weakly insulating, amorphous nickel-silicon films located just below the metal-insulator transition (MIT). The conductivity follows a simple CT z power-law dependence with z ≈ 1/2 over a large temperature interval. In contrast, a Mott variable-range hopping expression could not be fitted successfully through these zero-field conductivity data. The CT z behaviour can be explained using the three-dimensional (3D) electron-electron interaction (EEI) theory. The negative magnetoconductance data observed in these weakly insulating films can be fitted nicely using only the 3D EEI theory. A crossover of the conductivity from the simply power-law CT z dependence at high temperatures to an activated hopping-law dependence in the liquid helium temperature region is observed; this transition is attributed to changes in the energy dependence of the density of states near the Fermi level. The conductivity of these weakly insulating films can be fitted well over three decades of temperature using an empirical scaling expression suggested by Möbius et al.

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