Critical parameters of percolation in metal-dielectric diamond-like composites of atomic scale

The stabilized atomic scale composites ‘diamond-like carbon-metal’ are virtually ideal metal-dielectric percolating systems. The metals may be introduced in the diamond-like dielectric during its growth in a combined plasma and molecular beam deposition process. The maximum metal concentration and temperature limiting the composite stability depend on the atom radius and metal-matrix interaction. The percolation threshold in ([Cr,Fe,Ni]-C) composites corresponds to the theoretical value X_c=0.25 with critical exponent t=1.44, while in (W–C), (Hf–C), (Nb–C) composites the critical parameters of percolation are X_c=0.10, 1.25≤t≤2.0. A possible reason for this giant shift of percolation threshold is a self-organized redistribution of relatively large metallic atoms.