ELECTRON-TRANSPORT IN PERCOLATING GOLD-FILMS

Thin gold films with thicknesses below t=10 nm condensed at T=300 K on to amorphous carbon layers exhibit large channel structures which incr ease in size approaching the percolation threshold for p>p(c). The top ographies of the percolating films show fractal properties as obtained from direct analysis of electron micrographs. For the same films we c arried out magnetoresistance (MR) measurements at low temperatures (50 mK<T<30K) and compared these data with those from gold films with no voids or channels (t>10 nm). For both films we find the phase coherenc e length below 0.5 K to be temperature independent which we interpret as arising from spin scattering at magnetic impurities.