摘要:
The friction coefficients of diamond and hydrogen-free diamond-like carbon films were reported to be in an intermediate range, from 0.2 to 0.4, in oxygen atmosphere, but the mechanism has not been explored. Herein, by using first-principles calculations, we attempt to fill this gap by providing atomistic insights into the bonding behaviors of oxygen atom(s) at interfaces constructed by two self-mated diamond (001) or (111) surfaces. The effect of the interfacial oxygen coverage on the optimized interfacial structures is highlighted. The results show that if the oxygen coverage is not higher than 0.5, the two surfaces tend to be connected by oxygen atoms by formation of CeOeC bonds, and thus high friction is expected. Otherwise, the two surfaces keep being separated, and thus low friction is expected. The interfacial electron distributions are manifested to underlie the structural optimizations. Insights gained here together with the findings of T. E. Derry et al. concerning oxygen coverage on diamond surfaces contribute to understanding the unusual frictional behavior of hydrogen-free diamond-like carbons in oxygen atmosphere.
-
期刊:
CARBON
-
分类:
物理学
>>
普通物理:统计和量子力学,量子信息等
-
引用:
ChinaXiv:201705.00413
(或此版本
ChinaXiv:201705.00413V1)
DOI:10.12074/201705.00413V1
CSTR:32003.36.ChinaXiv.201705.00413.V1
- 推荐引用方式:
Wang, LP [Wang, Liping][ 1,3 ],Cui, LC [Cui, Longchen][ 2,3 ],Lu, ZB [Lu, Zhibin][ 3 ],Zhou, H [Zhou, Hui][ 2 ].(2017).Understanding the unusual friction behavior of hydrogen-free diamond-like carbon films in oxygen atmosphere by first-principles calculations.中国科学院科技论文预发布平台.[ChinaXiv:201705.00413]
(点此复制)