Mechanical and physical properties of amorphous carbon-based alloys

Silane and nitrogen were added in the gas phase in a technique suitable for the deposition of a-C and a-C:H films, even in the absence of an external bias. It has been shown that nitrogen dehydrogenates the films and weakens CH bonds, while a small amount of silane is sufficient to achieve high values (up to 40 GPa) of hardness, as measured by nanoindentation of thick films. This result has to do with the kinetics of deposition and not the alloying itself. Preliminary results concerning a new alloy (a-C:H:Si:N) are discussed too.