Structure of sp2dominant a-C film with superhardness

The mechanical properties of amorphous carbon (a-C) films strongly depend on the film structure. This paper reports on the superhardness of an a-C film resulting from a sp2 dominant microstructure synthesized by magnetron sputtering. The inherent medium compressive stress ensures the film is deposited with a thickness of 1.5 µm. The microstructure of the film with sp2 sites embedded in the amorphous matrix is responsible for the high elastic recovery and superhardness behaviour.