Near‐Edge X‐Ray Absorption Fine Structure of Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Films Prepared by Pulsed Laser Deposition

Ohmagari, Shinya; Yoshitake, Tsuyoshi; Nagano, Akira; Al-Riyami, Sausan; Ohtani, Ryota; Setoyama, Hiroyuki; Kobayashi, Eiichi; Nagayama, Kazuaki

doi:10.1155/2009/876561

Cited by 43 publications

(29 citation statements)

References 30 publications

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“…The partial electron yield (PEY) mode [ 61 ] was used in the NEXAFS measurement. Therefore, -CH n ( n = 1–3) was included in the peak of C 1s → σ* together with -C; however, as C-H is observed at 287 eV [ 62 , 63 , 64 ] or 287.5 eV [ 65 ], C-H was not included in the sp 3 ratio in this NEXAFS analysis.…”

Section: Methods Of Characterizationmentioning

confidence: 99%

Properties and Classification of Diamond-Like Carbon Films

Hiratsuka²,

et al. 2021

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Diamond-like carbon (DLC) films have been extensively applied in industries owing to their excellent characteristics such as high hardness. In particular, there is a growing demand for their use as protective films for mechanical parts owing to their excellent wear resistance and low friction coefficient. DLC films have been deposited by various methods and many deviate from the DLC regions present in the ternary diagrams proposed for sp3 covalent carbon, sp2 covalent carbon, and hydrogen. Consequently, redefining the DLC region on ternary diagrams using DLC coatings for mechanical and electrical components is urgently required. Therefore, we investigate the sp3 ratio, hydrogen content, and other properties of 74 types of amorphous carbon films and present the classification of amorphous carbon films, including DLC. We measured the sp3 ratios and hydrogen content using near-edge X-ray absorption fine structure and Rutherford backscattering-elastic recoil detection analysis under unified conditions. Amorphous carbon films were widely found with nonuniform distribution. The number of carbon atoms in the sp3 covalent carbon without bonding with hydrogen and the logarithm of the hydrogen content were inversely proportional. Further, we elucidated the DLC regions on the ternary diagram, classified the amorphous carbon films, and summarized the characteristics and applications of each type of DLC.

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Section: Methods Of Characterizationmentioning

confidence: 99%

Properties and Classification of Diamond-Like Carbon Films

Hiratsuka²,

et al. 2021

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“…Each of the spectrum consists primarily of the two-edge structures; one is the pre-edge resonance near 285 eV assigned to the transition from the C 1s orbital to the unoccupied p* orbitals principally originating from the sp 2 and sp sites, and the other broadband structure between 288 and 335 eV is related to C 1s!r * transitions at sp, sp 2 , and sp 3 sites. 11,20 The sp…”

mentioning

confidence: 99%

Structural analysis of amorphous carbon films by spectroscopic ellipsometry, RBS/ERDA, and NEXAFS

Zhou

Suzuki

Nakajima

et al. 2017

Applied Physics Letters

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The structural analysis of amorphous carbon films is not only the premise of their unique properties applied in the industrial fields but also the indispensable element on their classification. In this letter, we refurbished the classification of amorphous carbon films based on the optical constants in terms of the refractive index (n) and the extinction coefficient (k). In the selected photon energy range, we defined the maximum of n (En-max) and k at a value more than 10−4 (Ek) to explore the relationship between different classification schemes for amorphous carbon films deposited by different techniques. We found that Ek and En-max of the deposited amorphous carbon films have an exponential relationship with the hydrogen contents. Thus, the spectroscopic ellipsometry analysis can also be used as one of the effective methods for the structural evaluation of the amorphous carbon films.

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“…The broadening of the p * peak, in which the peak tail on the high energy side is extended to 286-287 eV, can originate from the functional groups. Actually, the r Ã CAH transition occurs in the approximate range of 286-288 eV [49][50][51], and the p Ã CAO and the r Ã CAO transitions are located over 287-291 eV [52][53][54]. Accordingly, we have concluded that the amount of oxygen-containing functional groups is below the detection limit in our experiments, and that the r-dangling bonds are mainly terminated by hydrogen atoms.…”

Section: Discussionmentioning

confidence: 67%

“…Thus, hydrogen and oxygen are considered to be plausible species that terminate dangling bonds. According to former studies, various transitions related to the states of functional groups [49][50][51][52][53][54] can occur in addition to the interlayer state [42,55,56] in the intermediate between the p * and the r * regions. In the present study, the PEY spectra of the pristine sample had a broad feature around 288 eV regardless of the angle of X-ray incidence, whereas the TEY spectra did not have such a feature, as shown in the insets of Fig.…”

Section: Discussionmentioning

confidence: 99%