Ring formation and the structural and electronic properties of tetrahedral amorphous carbon surfaces

Dong, Jianjun; Drabold, D. A.

doi:10.1103/physrevb.57.15591

Cited by 37 publications

(16 citation statements)

References 40 publications

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“…The structural properties of the relaxed a-C film are summarized in Table I. Our structure has slightly lower sp 3 content compared to a 213 atom a-C slab studied by Dong and Drabold [16] using a more approximate nonself-consistent Harris functional method. The lower sp 3 in our model is likely because we use a random C network as a starting configuration for bulk a-C, whereas Dong and Drabold use a fully sp 3 coordinated network.…”

Section: (Received 28 July 1999)mentioning

confidence: 99%

Nitrogen Doping of Amorphous Carbon Surfaces

Kaukonen

Nieminen

Pöykkö³

et al. 1999

Phys. Rev. Lett.

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The surface properties of amorphous carbon (a-C) are studied using first-principles electronic structure methods. The effect of nitrogen doping near the surface and, in particular, the effect of nitrogen on the work function is studied by doing a series of nitrogen substitutions near the surface. It is found that the work function is reduced by nitrogen doping of the a-C surface at "on top of the surface" sp 1 and sp 2 sites. Nitrogen doping by low energy ion bombardment is suggested as a doping method to minimize work function of the a-C surfaces.

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Section: (Received 28 July 1999)mentioning

confidence: 99%

Nitrogen Doping of Amorphous Carbon Surfaces

Kaukonen

Nieminen

Pöykkö³

et al. 1999

Phys. Rev. Lett.

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“…6 Similarly, simulations performed on tetrahedral amorphous carbon surfaces also indicate the formation of rings and chains. 7 Additionally, for the carbon cluster anions C n Ϫ there is sufficient experimental evidence to indicate the existence of chains for nр10, and rings for the larger structures. 8 From a theoretical point of view as well carbon chains and rings have elicited a large amount of interest.…”

Section: Introductionmentioning

confidence: 99%

Ab initiomany-body calculations on infinite carbon and boron-nitrogen chains

2002

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In this paper we report first-principles calculations on the ground-state electronic structure of two infinite one-dimensional systems: ͑a͒ a chain of carbon atoms and ͑b͒ a chain of alternating boron and nitrogen atoms. Meanfield results were obtained using the restricted Hartree-Fock approach, while the many-body effects were taken into account by second-order Mo "ller-Plesset perturbation theory and the coupled-cluster approach. The calculations were performed using 6-31G** basis sets, including the d-type polarization functions. Both at the Hartree-Fock ͑HF͒ and the correlated levels, we find that the infinite carbon chain exhibits bond alternation with alternating single and triple bonds, while the boron-nitrogen chain exhibits equidistant bonds. In addition, we also performed density-functional-theory-based local-density-approximation ͑LDA͒ calculations on the infinite carbon chain using the same basis set. Our LDA results, in contradiction to our HF and correlated results, predict a very small bond alternation. Based upon our LDA results for the carbon chain, which are in agreement with an earlier LDA calculation ͓E.J. Bylaska, J.H. Weare, and R. Kawai, Phys. Rev. B 58, R7488 ͑1998͔͒, we conclude that the LDA significantly underestimates Peierls distortion. This emphasizes that the inclusion of many-particle effects is very important for the correct description of Peierls distortion in onedimensional systems.

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“…Эти участки графитовой структуры должны уменьшать поверхностную энергию, этому способствует и ориентация плоскостей, гексагональные плоскости па-раллельны поверхности пленки. Эти рассуждения под-тверждаются моделированием [21,22]. Второй фактор, который необходимо учитывать при анализе механизма фазового перехода, это высокие упругие напряжения, существующие в тонких пленках [23].…”

Section: образование графитовой фазыunclassified

Graphite formation in diamond-like carbon thin films

Плотников¹,

Dem’yanov²,

Yartsev³

et al. 2017

LoM

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In the present work, particularities of the formation and structure of a graphite phase appearing in a thin amorphous diamondlike carbon (ta-C) film were studied using the method of high resolution electron microscopy. In order to obtain a thin carbon film, a neodymium laser NTS300 with a wavelength of 1064 nm was used. The film was deposited on a glass substrate in the process of a direct evaporation of a graphite target. Study of the graphite phase formation in the film was carried out using the high resolution transmission electron microscopy that allowed for a direct observation of the thin film atomic structure. Electron diffraction analysis shows that in local areas of a thin film a phase transition from amorphous diamond-like ta-C state to graphite occurs. Single crystals of graphite are oriented so that their basic hexagonal planes are parallel to the film surface. This is due to the fact that sp 3 bonds are metastable and can be unstable, particularly on the film surface. Therefore, the transition of sp 3 bonds to sp 2 ones with the formation of planar complexes with a ring structure initially occurs on the film surface. The growth of a graphite crystal nucleus in the ta-C matrix increases the stress and stabilizes the diamond state. Due to this, the graphite phases form dominantly on the film edges. Analysis of electron diffraction patterns has shown that the interplanar spacings depend on the orientation of the planes relative to the film edge. Measurements of interplanar spacings reveals a complicated character of the stress state of the graphite lattice in the thin film. Along with tension-compression stresses, shear stresses are present and they result in a change of the angles between carbon interatomic bonds.Keywords: carbon film, diamond-like structure, amorphous carbon, graphite. Образование графита в алмазоподобных тонких углеродных пленкахПлотников В. А. † , Демьянов Б. Ф., Ярцев В. И., Соломатин К. В. † plotnikov@phys.asu.ru Алтайский государственный университет, пр. Ленина 61, 656049, Барнаул, Россия В работе методом высокоразрешающей электронной микроскопии проведено исследование особенностей образо-вания и структуры графитовой фазы, возникающей в тонкой аморфной алмазоподобной (ta-C) углеродной плен-ке. Для получения тонкой углеродной пленки использовался мощный неодимовый лазер NTS300 с длиной волны 1064 нм. Углерод осаждался на стеклянной подложке из силикатного стекла в процессе прямого испарения гра-фитовой мишени. Исследование образования графитовой фазы в пленке проводилось методом высокоразрешаю-щей электронной микроскопии, позволяющей использовать прямое наблюдение атомной структуры тонкой плен-ки. Электронографический анализ показал, что в локальных областях тонкой пленки происходит фазовый переход из аморфного алмазоподобного ta-C состояния в графит. Монокристаллы графита ориентированы так, что базисная гексагональная плоскость параллельна поверхности пленки. Это связано с тем, что связи sp 3 метастабильны и могут быть неустойчивы, особенно на поверхности пленки. Поэтому переход...

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Ring formation and the structural and electronic properties of tetrahedral amorphous carbon surfaces

Cited by 37 publications

References 40 publications

Nitrogen Doping of Amorphous Carbon Surfaces

Nitrogen Doping of Amorphous Carbon Surfaces

Ab initiomany-body calculations on infinite carbon and boron-nitrogen chains

Graphite formation in diamond-like carbon thin films

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