  Diamond-Like Carbon (DLC) films have been shown to demonstrate various
tribological behaviors: in ultra-high vacuum (UHV), with either friction
coefficients as low as 0.01 or less and very mild wear, or very high friction
coefficients (>0.4) and drastic wear. These behaviors depend notably on gaseous
environment, hydrogen content of the film [1], and on its viscoplastic
properties [2,3]. A relation between superlow friction in UHV and
viscoplasticity has indeed been established for a-C:H films and confirmed for a
fluorinated sample (a-C:F:H). In this study, nanoindentation and nanoscratch
tests were conducted in ambient air, using a nanoindentation apparatus, in
order to evaluate tribological behaviors, as well as mechanical and
viscoplastic properties of different amorphous carbon films.
