Optical properties of a-C:H thin films modified by Ti and Ag

Structure and optical properties of amorphous diamond-like carbon (a-C: H) thin films modified with Ag, Ti and Ag + Ti metal impurities are studied. The films were prepared by ion-plasma magnetron sputtering of combined polycrystalline graphite and metal target in the mixture of Ar and CH4 gases. AFM, SEM and TEM methods show that a-C:H < Ag+Ti > films are heterogeneous, nanostructured and characterized by the presence of silver nanoclusters on the surface sized similar to 60 nm and both Ti and Ag nanoclusters with a mean size similar to (2 divided by 3) nm in the bulk of films. It was found that in a-C:H < Ag+Ti > films as well as in a-C:H < Ag > films plasma resonance absorption due to excitation of surface plasmons in silver nanoclusters in the visible region of spectrum takes place. Intensity of the resonance absorption in the a-C:H < Ag+Ti > films increases with increase in concentration of silver. The results are important for produce of nanomaterials with nonlinear optical properties based on the amorphous diamond-like carbon films containing metal nanoclusters.