Growth regimes and metal enhanced 6-fold ring clustering of carbon in carbon–nickel composite thin films

Abrasonis, G.; Krause, Matthias; Mücklich, A.; ̆ková, K. Sedlac; Radnóczi, G.; Kreißig, U.; Kolitsch, A.; Möller, W.

doi:10.1016/j.carbon.2007.09.044

Cited by 65 publications

(122 citation statements)

References 68 publications

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“…The ability of the metals to act as catalysts is often explained by the formation of a metastable carbide phase which decomposes into a stable carbide and graphite. Nevertheless, Abrasonis et al found for a-C:Ni films an enhanced aromatic clustering independently from the Ni phase state 21 . The importance of metals acting as catalysts in the synthesis of carbon nanotubes [53][54][55] and other graphitic materials [56][57][58] is well known even if there is still discussion about the mechanism.…”

Section: Discussionmentioning

confidence: 97%

“…Carbon atom surface diffusion on metal-based particles is proposed to be a key step during carbon nanotube growth for the formation of graphitic structures 55 and is believed to be also responsible for enhanced aromatic clustering during growth of a-C:Ni films 21 . In comparison, the metal content of our films is relatively low and no metallic or carbide particles are formed during deposition 17,22 .…”

Section: Discussionmentioning

confidence: 99%

“…An increase in I(D)/I(G) ratio and G peak position concomitantly with W or Ti concentration has been observed 15,20 . Abrasonis et al 21 reported detailed about the effect of Ni-doping and substrate temperature during growth of a-C:Ni films, but the Ni concentration was fixed to 30 %.…”

Section: Introductionmentioning

confidence: 99%

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Influence of doping (Ti, V, Zr, W) and annealing on the sp2 carbon structure of amorphous carbon films

Adelhelm

Balden

Rinke

et al. 2009

Journal of Applied Physics

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The influence of the transition metal (Ti, V, Zr, W) doping on the carbon matrix nanostructuring during the thin film growth and subsequent annealing is investigated. Pure and metal-doped amorphous carbon films (a-C, a-C:Me) were deposited at room temperature by non-reactive magnetron sputtering. The carbon structure of as-deposited and post-annealed (up to 1300 K) samples was analyzed by X-ray diffraction (XRD) and Raman spectroscopy.The existence of graphene-like regions in a-C is concluded from a (10) diffraction peak. A comparison of the XRD and Raman results suggests that XRD probes only the small amount of 2-3 nm large graphene-like regions, whereas the majority of the sp 2 phase is present in smaller distorted aromatic clusters which are probed only by Raman spectroscopy. Annealing leads to an increase of the graphene size and the aromatic cluster size. During the carbon film growth the addition of metals enhances ordering of sp 2 carbon in sixfold aromatic clusters compared to a-C, Ti and Zr showing the strongest effect, W the lowest. This order qualitatively corresponds with the catalytic activity of the respective carbides found during graphitization of carbide-doped graphites published in the literature. With annealing, carbide crystallite formation and growth occurs in a-C:Me films, which destroys the initial carbon structure, reduces the size of the initially formed aromatic clusters and the differences in carbon structure introduced by different dopants. For high annealing temperatures the carbon structure of a-C:Me films is similar to that of a-C, and is determined only by the annealing temperature.2

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Section: Discussionmentioning

confidence: 97%

Section: Discussionmentioning

confidence: 99%

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Influence of doping (Ti, V, Zr, W) and annealing on the sp2 carbon structure of amorphous carbon films

Adelhelm

Balden

Rinke

et al. 2009

Journal of Applied Physics

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“…28,29 Thermodynamic forces lead to a precipitation of metal carbide or pure metal phase in the carbon matrix. [24][25][26]33,43,44 Carbon ions continue to be deposited onto the carbon matrix or onto the clusters themselves. Eventually excess carbon segregates to surfaces of and spaces between the clusters, encapsulating the metal and forming a continuous carbon layer.…”

Section: -4mentioning

confidence: 99%

“…25,33 Any considerable surface diffusion destroys the periodic precipitation pattern 33 and results in the formation of columnar structures. 19,20,22,23,33,43 During film growth, short-range ballistic displacement of atoms takes place in a near-surface region ͑ϳ1 -2 nm thick͒ due to hyperthermal ion impacts. 28,29 Thermodynamic forces lead to a precipitation of metal carbide or pure metal phase in the carbon matrix.…”

Section: -4mentioning

confidence: 99%

Nanoscale precipitation patterns in carbon–nickel nanocomposite thin films: Period and tilt control via ion energy and deposition angle

Abrasonis

Oates

Kovács

et al. 2010

Journal of Applied Physics

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Periodic precipitation patterns in C:Ni nanocomposites grown by energetic ion codeposition are investigated. Films were grown at room temperature by ionized physical vapor deposition using a pulsed filtered cathodic vacuum arc. We reveal the role of the film composition, ion energy and incidence angle on the film morphology using transmission electron microscopy and grazing incidence small angle x-ray scattering. Under these growth conditions, phase separation occurs in a thin surface layer which has a high atomic mobility due to energetic ion impacts. This layer is an advancing reaction front, which switches to an oscillatory mode, producing periodic precipitation patterns. Our results show that the ion induced atomic mobility is not random, as it would be in the case of thermal diffusion but conserves to a large extent the initial direction of the incoming ions. This results in a tilted pattern under oblique ion incidence. A dependence of the nanopattern periodicity and tilt on the growth parameters is established and pattern morphology control via ion velocity is demonstrated.

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Morphology and Structure of C:Co, C:V, and C:Cu Nanocomposite Films

Berndt

Krause

Abrasonis

et al. 2009

Plasma Processes & Polymers

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The influence of transition metals (TM) type on the encapsulating carbon (C) medium during the growth of C:TM (TM = V, Co and Cu) composite films with a metal content of ∼30 at.‐% grown by ion beam co‐sputtering in the temperature range of RT‐500 °C is investigated by means of X‐ray diffraction, transmission electron microscopy and Raman spectroscopy. The nanostructure of both C:TM nanocomposite constituents is strongly affected by the TM type and the growth temperature. The nanoparticle size, shape, and phase depend on these parameters. Raman spectroscopy shows that all three metals enhance six‐fold ring clustering of the carbon phase independent of the nanoparticle type, size, shape and phase, and the effect is most pronounced at lower temperatures.

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Growth regimes and metal enhanced 6-fold ring clustering of carbon in carbon–nickel composite thin films

Cited by 65 publications

References 68 publications

Influence of doping (Ti, V, Zr, W) and annealing on the sp2 carbon structure of amorphous carbon films

Influence of doping (Ti, V, Zr, W) and annealing on the sp2 carbon structure of amorphous carbon films

Nanoscale precipitation patterns in carbon–nickel nanocomposite thin films: Period and tilt control via ion energy and deposition angle

Morphology and Structure of C:Co, C:V, and C:Cu Nanocomposite Films

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