Nanostructured coatings of metal containing diamond-like carbon films deposited by femtosecond pulsed laser ablation

Nanocrystallized metal (Me)/carbon-based films (a-C:Me) have been deposited by femtosecond pulsed laser ablation (PLD). The films have been obtained by ablating alternatively and sequentially graphite and metallic targets in vacuum conditions, with an amplified femtosecond Ti:sapphire laser (wavelength 800 nm, pulsed duration of 150 fs). The metals selected, regarding of their opposite chemical affinity with carbon, are nickel and tantalum. The deposition procedure allowed to control accurately the metal concentration introduced in the carbonaceous matrix, in the 15 at.% range. The composition and nanostructure of the films have been characterized by X-ray photoelectron spectroscopy, grazing incident angle X-ray diffraction and energy filtered transmission electron microscopy. The nanocomposite coatings contain metallic clusters in the 10–250 nm size range, embedded in the carbonaceous network. The interface between the metallic clusters and the carbon matrix depends on the chemical affinity of the metal in respect to carbon.