Water adsorption on phosphorous-carbide thin films
Amorphous phosphorous-carbide films have been considered as a new tribological coating material with unique electrical properties. However, such CP x films have not found practical use until now because they tend to oxidize/hydrolyze rapidly when in contact with air. Recently, we demonstrated that C...
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Published in | Surface & coatings technology Vol. 204; no. 6; pp. 1035 - 1039 |
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Main Authors | , , , , , , , |
Format | Journal Article Conference Proceeding |
Language | English |
Published |
Amsterdam
Elsevier B.V
25.12.2009
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | Amorphous phosphorous-carbide films have been considered as a new tribological coating material with unique electrical properties. However, such CP
x
films have not found practical use until now because they tend to oxidize/hydrolyze rapidly when in contact with air. Recently, we demonstrated that CP
x
thin films with a fullerene-like structure can be deposited by magnetron sputtering, whereby the structural incorporation of P atoms induces the formation of strongly bent and inter-linked graphene planes. Here, we compare the uptake of water in fullerene-like phosphorous-carbide (FL-CP
x
) thin films with that in amorphous phosphorous-carbide (a-CP
x
), and amorphous carbon (a-C) thin films. Films of each material were deposited on quartz crystal substrates by reactive DC magnetron sputtering to a thickness in the range 100–300 nm. The film microstructure was characterized by X-ray photoelectron spectroscopy, and high resolution transmission electron microscopy. A quartz crystal microbalance placed in a vacuum chamber was used to measure their water adsorption. Measurements indicate that FL-CP
x
films adsorbed less water than the a-CP
x
and a-C ones. To provide additional insight into the atomic structure of defects in the FL-CP
x
and a-CP
x
compounds, we performed first-principles calculations within the framework of density functional theory. Cohesive energy comparison reveals that the energy cost formation for dangling bonds in different configurations is considerably higher in FL-CP
x
than for the amorphous films. Thus, the modeling confirms the experimental results that dangling bonds are less likely in FL-CP
x
than in a-CP
x
and a-C films. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0257-8972 1879-3347 1879-3347 |
DOI: | 10.1016/j.surfcoat.2009.06.003 |