Raman spectroscopy on amorphous carbon films

Schwan, J.; Ulrich, S.; Batori, V.; Ehrhardt, H.; Silva, S. Ravi P.

doi:10.1063/1.362745

Cited by 1,248 publications

(692 citation statements)

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“…The Raman spectra of these films as well as for the amorphous carbon films deposited at higher flux ratios are similar to Raman spectra of highly disordered graphitic structures. 38 This is surprising for carbon films containing more than 60% sp 3 , but it should be noted that the Raman sensivity of diamond is 50ϫ less than that for graphite. 39 In order to obtain more information on the microstructure of these films a TEM analysis was performed.…”

Section: Resultsmentioning

confidence: 96%

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Stress-induced formation of high-density amorphous carbon thin films

Schwan

Ulrich

Theel

et al. 1997

Journal of Applied Physics

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115

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Amorphous carbon films with high sp 3 content were deposited by magnetron sputtering and intense argon ion plating. Above a compressive stress of 13 GPa a strong increase of the density of the carbon films is observed. We explain the increase of density by a stress-induced phase transition of sp 2 configured carbon to sp 3 configured carbon. Preferential sputtering of the sp 2 component in the carbon films plays a minor role compared to the sp 2 ⇒sp 3 transition at high compressive stress formed during the deposition process. Transmission electron microscopy shows evidence of graphitic regions in the magnetron sputtered/Ar plated amorphous carbon thin films. Differences in the microstructure of the tetrahedral amorphous carbon ͑ta-C͒ films deposited by filtered arc and mass selected ion beam; and those films deposited using magnetron sputtering combined with intense ion plating can be used to explain the different electronic and optical properties of both kinds of ta-C films. © 1997 American Institute of Physics. ͓S0021-8979͑97͒09422-X͔ INTRODUCTIONCarbon films have been of considerable research interest since Aisenberg and Chabot 1 deposited the first hard, diamondlike amorphous carbon films. Amorphous carbon films with a high fraction of sp 3 hybridized carbons have been deposited by filtered cathodic vacuum arc ͑FCVA͒ 2-4 and mass selected ion beams. 5-8 C ϩ ions are used to deposit the amorphous carbon films by both techniques. Different mechanisms for the formation of the sp 3 rich phase have been proposed such as the shallow implantation process ͑subplantation͒ by Lifshitz et al.,5,6 selective sputtering processes by Reinke and Kuhr 9 ͑discussed for c-BN͒, and stressinduced phase transition processes by McKenzie et al. 3,10 Analytical expressions for the subplantation process describing the formation of stress and the densification have been proposed by Davis 11 and Robertson. 12 The basic idea of the models by Davis and Robertson is that a carbon ion needs at least the displacement energy to penetrate into the carbon film leading to a densification of subsurface layers of the evolving film. 6 But, not all the energy of the energetic carbon ion is used for penetration ͑displacement processes͒. Part of the ion energy is used by momentum transfer collisions which results in a thermal spike. Davis 11 and Robertson 12 modified calculations of Windischmann 13 by allowing implanted carbon atoms to relax to the film surface, due to the high localized temperature generated by the impinging C ϩ ions in the thermal spike. Yet, questions as to the validity of a thermal spike at ion energies of a few hundred electron volts in a low elemental mass material remains unanswered. Nevertheless, at such impact energies several thousand vibrations are involved for a time period of the order of 10 Ϫ12 s. 14 Dense and highly tetrahedral amorphous carbon films have also been deposited by the laser ablation technique, 15,16 by dual ion beam technique, 17 and recently by magnetron sputtering together with intense ion plating ͑MS/I...

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Section: Resultsmentioning

confidence: 96%

“…3 Although TEM showed that most of the carbon film is amorphous such regions in the carbon films may be responsible for the low optical gap and observed Raman scattering. 38 The rather broad G-line width of the Raman data may be due to the high compressive stress in the films. 38 These findings may also explain the ESR results presented.…”

Section: Resultsmentioning

confidence: 99%

Stress-induced formation of high-density amorphous carbon thin films

Schwan

Ulrich

Theel

et al. 1997

Journal of Applied Physics

Self Cite

115

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“…(Dresselhaus & Dresselhaus 1982). The D4 band was shown to be related to the sp 3 C content (Schwan et al 1996) or was either assigned to polyenic-like sp 2 C=C stretching motions (Shirakaw et al 1973) or more vaguely to mixed sp 2 -sp 3 CC motions (Bacsa et al 1993;Dippel et al 1999) because of the similarities to the Raman spectra of polyenes. The second-order Raman spectra in the 2200−3600 cm −1 region are shown in Fig.…”

Section: Raman Spectroscopymentioning

confidence: 99%

Nanostructuration of carbonaceous dust as seen through the positions of the 6.2 and 7.7μm AIBs

Carpentier

Féraud

Dartois

et al. 2012

A&A

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“…Raman spectroscopy has been used as a technique to characterize DLC coatings, and their wear debris in the literature [37][38][39]. Renishaw inVia Raman microscope was used to analyze the structural modifications in the wear tracks of the a-C:15H…”

Section: Coating Wear Analysismentioning

confidence: 99%

Tribological performance and tribochemical processes in a DLC/steel system when lubricated in a fully formulated oil and base oil

Kosarieh

Morina

Lainé

et al. 2013

Surface and Coatings Technology

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Abstract:Diamond-like carbon (DLC) coatings show extremely good promise for a number of applications in automotive components as they exhibit excellent tribological properties such as low friction and good wear resistance. This can impact on improved fuel economy and durability of the engine components. Much work has been reported on the dry sliding of DLC coatings with less so in lubricated contacts and, as such, there is a need to further understand the tribochemistry of lubricated DLC contacts. Commercially-available oils are normally optimized to work on ferrous surfaces. Previous studies on DLC lubricated contacts have tended to use model oil systems rather than fully formulated lubricants and from this an interesting picture of lubrication mechanisms is emerging. Optimising compatibility between a surface and a set of lubricant additives may lead to excellent durability (wear) as well as increased fuel economy (low friction). In this work, the friction and wear properties of a DLC coating under boundary lubrication conditions have been investigated and the tribological performance compared with that of an uncoated steel system. A pin-on-plate tribotester was used to run the experiments using High speed steel (HSS) M2 grade plates coated with 15 at.% hydrogenated DLC (a-C:15H) sliding against cast iron pins. A Group III mineral base oil, fully synthetic Group IV PAO and four different fully formulated oils were used in this study. Furthermore optical and scanning electron microscopes (SEM) were used to observe the wear scar and to assess the durability of the coatings. Energy-Dispersive X-ray analysis (EDX), X-ray Photoelectron Spectroscopy (XPS) and Raman spectroscopy analyses were performed on the tribofilms to understand the tribochemical interactions between oil additives and the a-C:15H coating.This study show that the durability of the a-C:15H coating strongly depends on the selected additive package in the oils. In addition the effect of detergent, dispersant and antioxidants on the performance of the Molybdenum-based friction modifier (Mo-FM) and ZDDP anti-wear additive were investigated and results are reported in this paper.

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Raman spectroscopy on amorphous carbon films

Cited by 1,248 publications

References 38 publications

Stress-induced formation of high-density amorphous carbon thin films

Stress-induced formation of high-density amorphous carbon thin films

Nanostructuration of carbonaceous dust as seen through the positions of the 6.2 and 7.7μm AIBs

Tribological performance and tribochemical processes in a DLC/steel system when lubricated in a fully formulated oil and base oil

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