Figure 3.

Representative surface roughness power spectra for the analyzed sample calculated by the AFM images reported in Fig. 1:afor the sample with a thickness of 2 nmbof 8 nm,cof 14 nm,dof 20 nm,eof 26 nm,fof 32 nm of Au respectively. The continuous lines represent the fit by Eq. 4. The values ofγ_ireported as insets are calculated by such fits