| AVS 64th International Symposium & Exhibition | |
| Tribology Focus Topic | Thursday Sessions |
| Session TR+AC+TF+VT-ThM |
| Session: | Lubricant, Coatings, and Biotribology |
| Presenter: | Carlos Figueroa, UCS, Brazil |
| Authors: | F.G. Echeverrigaray, UCS, Brazil S.R. Sales de Mello, UCS, Brazil A.F. Michels, UCS, Brazil F. Alvarez, UNICAMP, Brazil C.A. Figueroa, UCS, Brazil |
| Correspondent: | Click to Email |
The friction phenomenon is a complex manifestation of the nature. In spite of phenomenological laws can describe the friction force at different scales, the fundamental physical understandings of such a phenomenon do not have consensus. Phenomena such as phononic, electronic, magnetic, and also electrostatic effects and models were developed in order to explain the meta- and nano-friction behavior of materials. In this work, we report the friction behavior of a diamond spherical dome sliding on different amorphous carbon thin films containing different amounts of hydrogen and/or deuterium inspecting at the meta-nanoscale indentation. Two important situation are reported. Firstly, for samples where hydrogen was replaced by deuterium in the thin film bulk, the friction coefficient decreases for increasing deuterium included in the carbon underneath structure. Secondly, for samples where hydrogen content is increased on the surface, the friction coefficient decreases with the increasing of the ratio H/C at the surface. In this paper, we discuss two different physical mechanisms describing these peculiar experimental results: dissipation effects associated with phonon coupling and van der Waals forces contributions coexisting and determining the friction behaviour of a-C:H/D for the cited studied situations.