TY - JOUR
T1 - Friction and wear at nanometer scale
T2 - A comparative study of hard carbon films
AU - Prioli, R.
AU - Chhowalla, M.
AU - Freire, F. L.
N1 - Funding Information:
This work is partially supported by the Brazilian Agencies: Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), Coordenação de Aperfeiçoamento de Pessoal de Nı́vel Superior (CAPES) and Conselho Nacional de Desenvolvimento Cientı́fico e Tecnológico (CNPq). The authors also acknowledge Mrs P. Ayala for the assistance during wear measurements.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2003/12
Y1 - 2003/12
N2 - Tribological properties of nanostructured carbon (ns-C) and tetrahedral amorphous carbon (ta-C) thin films were investigated by friction force microscopy. It was found that the ns-C films have a smaller friction coefficient than ta-C films for relative humidity greater than 30%. In particular, at 40% of humidity, ns-C films have lower friction coefficient (0.11±0.02) than the ta-C films (0.13±0.02), which can be attributed to both the presence of closed graphite nanoparticles and the passivation of the dangling bonds at the ns-C surface. The friction coefficient did not vary as a function of the tip scanning velocity for both films. The nanoscale wear was studied in a very low force regime, in the range of nanonewton, using an atomic force microscope (AFM) with a Si3N4 tip and with forces in the range of micronewton with the AFM equipped with a stainless still cantilever and a diamond tip. The ns-C provides better wear resistance compared to ta-C films in the range of forces studied. The sp2-rich ta-C surface layer was easily scratched during the wear test in contrast to the ns-C films. The wear in ta-C in the low forces regime is attributed to the presence of this low density layer at the surface of the film due to subplantation of energetic ions during deposition while the better resistance to wear of ns-C films is attributed to its highly elastic nature.
AB - Tribological properties of nanostructured carbon (ns-C) and tetrahedral amorphous carbon (ta-C) thin films were investigated by friction force microscopy. It was found that the ns-C films have a smaller friction coefficient than ta-C films for relative humidity greater than 30%. In particular, at 40% of humidity, ns-C films have lower friction coefficient (0.11±0.02) than the ta-C films (0.13±0.02), which can be attributed to both the presence of closed graphite nanoparticles and the passivation of the dangling bonds at the ns-C surface. The friction coefficient did not vary as a function of the tip scanning velocity for both films. The nanoscale wear was studied in a very low force regime, in the range of nanonewton, using an atomic force microscope (AFM) with a Si3N4 tip and with forces in the range of micronewton with the AFM equipped with a stainless still cantilever and a diamond tip. The ns-C provides better wear resistance compared to ta-C films in the range of forces studied. The sp2-rich ta-C surface layer was easily scratched during the wear test in contrast to the ns-C films. The wear in ta-C in the low forces regime is attributed to the presence of this low density layer at the surface of the film due to subplantation of energetic ions during deposition while the better resistance to wear of ns-C films is attributed to its highly elastic nature.
KW - Nanostructures
KW - Scanning probes techniques
KW - Tetrahedral amorphous carbon
KW - Tribology
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U2 - 10.1016/j.diamond.2003.08.023
DO - 10.1016/j.diamond.2003.08.023
M3 - Article
AN - SCOPUS:0346121747
VL - 12
SP - 2195
EP - 2202
JO - Diamond and Related Materials
JF - Diamond and Related Materials
SN - 0925-9635
IS - 12
ER -