Achieving superlow friction with hydrogenated amorphous carbon: some key requirements

Finally, all hydrogenated amorphous carbon films do not lead to superlow friction under vacuum. The role of hydrogen content is known to be critical, but it appears to be strongly dependent on deposition process. Some mechanical properties of the films can also be correlated with friction reduction, like viscoplasticity. All these results suggest that surface rheological properties are of paramount importance in the achievement of superlow friction with a-C:H films.