alpha beta Experimental evidence for alpha - and beta -phases of pure crystalline C3N4 in films deposited on nickel substrates

Chen, Y; Guo, LP; Wang, EG

doi:10.1080/095008397179714

Cited by 82 publications

(20 citation statements)

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“…High resolute ion XPS scans of C (1s) and N (1s) peaks appear at 258 and 398.3 eV, respectively. The C1s and N1s binding energies in the film are very in agreement with the reported values for C (1s) and N (1s) peaks in the C 3 N 4 film by Chen et al [24]. The XPS spectra of C1s and N1s of the as-deposited and annealed films are shown in Fig.…”

Section: Xps Characteristicssupporting

confidence: 90%

“…This is also supported by the following XRD data. The lattice indices of a 0 and c 0 in our experiment are calculated to be 6.6145 A and 4.7297 A from the spacing of (221) and (221) planes, which are slightly larger than the values reported previously [23,24].…”

Section: Tem Observationcontrasting

confidence: 78%

“…3. Except strong peaks from the Si [24,26], indicating that the crystalline β-C 3 N 4 film has formed through the decomposition of the precursor film after heat treatment, and the XRD studies of the film clearly show that the C 3 N 4 film is (200) textured. A careful analysis of the indexed results for all six diffraction patterns indicated that the experimentally measured values of the interplanar spacings and the angles between the reciprocal-lattice planes agree well with those obtained from the calculation as shown in Table 1.…”

Section: Xrd Analysismentioning

confidence: 99%

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Crystalline carbon nitride film synthesized by ion beam assisted magnetron sputtering and thermal annealing in nitrogen gas

Liu

Bai

Pan

et al. 2015

Diamond and Related Materials

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Section: Xps Characteristicssupporting

confidence: 90%

Section: Tem Observationcontrasting

confidence: 78%

Section: Xrd Analysismentioning

confidence: 99%

See 1 more Smart Citation

Crystalline carbon nitride film synthesized by ion beam assisted magnetron sputtering and thermal annealing in nitrogen gas

Liu

Bai

Pan

et al. 2015

Diamond and Related Materials

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“…Carbon nitride compounds have been predicted [1] to exhibit extraordinary hardness, with some structures possibly being harder than diamond [2]. This has stimulated substantial research efforts in search of these materials, employing both experimental [3][4][5][6][7][8][9][10][11][12][13][14] and theoretical [2, 13,15,16] methods.…”

mentioning

confidence: 99%

NMR Chemical Shifts in Hard Carbon Nitride Compounds

Yoon

Pfrommer

Mauri³

et al. 1998

Phys. Rev. Lett.

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We show that NMR chemical shift spectroscopy could help to identify the crystalline phases of hard carbon nitride compounds. To this purpose we compute the NMR chemical shifts of defect zinc-blende, cubic, a2, b2, and graphitic C 3 N 4 with a newly developed ab initio method. The C shifts can be used to identify the CN bonds and to characterize C hybridization. The N shifts distinguish the a-C 3 N 4 from the b-C 3 N 4 phases, and indicate the presence of the graphitic phase. [S0031-9007 (98)05665-8] PACS numbers: 76.60.Cq, 71.15.Mb, 82.80.Ch Carbon nitride compounds have been predicted [1] to exhibit extraordinary hardness, with some structures possibly being harder than diamond [2]. This has stimulated substantial research efforts in search of these materials, employing both experimental [3-14] and theoretical [2,13,15,16] methods.Shortly after the possibility of high bulk modulus due to the expected short C-N bond lengths was recognized [1], the b-C 3 N 4 [2] and later the defect zinc-blende [16], a-C 3 N 4 [2], and cubic-C 3 N 4 [2] structures were proposed. The theoretical bulk moduli of these structures are 427, 425, 425, and 496 GPa, respectively. Experimental studies, mostly on thin films, followed soon, finding nanometer to micrometer sized crystals embedded usually in an amorphous matrix [3,6,8,11,12]. In several cases [3,6,11] the crystallites were believed to be of the b-C 3 N 4 structure, but it has been pointed out later [2] that the a-C 3 N 4 structure would comply better with the experimental data. Crystallites with a tetragonal structure [12] and even a monoclinic phase [12] have been reported recently. When using a chemical precursor technique, the defect zincblende structure also appears to form [13].In all experiments, the crystallites obtained are too small to allow a conclusive x-ray diffraction (XRD) analysis. Therefore, structural determinations have been done with XRD in combination with other techniques, e.g., electron diffraction [3,6,8,[11][12][13]], x-ray photoelectron spectroscopy [3,8,10], electron energy loss spectroscopy [4], backscattering [3,6,8,10,11,17], and transmission electron microscopy [6,11,12,14]. Still, the determination of the structure of the crystallites remains difficult and not definitive, often because of the obscuring signals from the amorphous matrix or the substrate [11].In this Letter, we suggest the use of nuclear magnetic resonance (NMR) chemical shift for C-N compound sample characterizations. NMR shift experiments are becoming increasingly popular for characterizing thin-film samples of amorphous carbon [18][19][20][21][22][23] and silicon [24]. By applying a recently developed ab initio method [25], we predict the NMR chemical shifts for C and N atoms of five different low-energy C 3 N 4 structures. Our theoretical data allow an interpretation of experimental NMR spectra, thereby opening a new way for C-N compound characterization. Unlike XRD, NMR experiments do not require long range order, and, as we shall see, should be able to clearly identify the sig...

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“…However, only a few authors have attempted the experimental synthesis of crystalline carbon nitrides [2][3][4][5], and in the majority of the studies the nitrogen content is much lower than 57 at.% and a disordered structure has been found [6][7][8][9]. Although serious problems have emerged during the production of the predicted crystalline phase, amorphous carbon nitride (a-CN x ) films exhibit significant characteristics, such as high hardness and elasticity [10,11], low friction coefficient [12,13], and infrared transparency [14], which stimulates the study of carbon nitride films.…”

Section: Introductionmentioning

confidence: 99%

Correlation between nitrogen incorporation and structural modification of hydrogenated carbon nitride films

Wang

Yang

Zhang

2008

Journal of Non-Crystalline Solids

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alpha beta Experimental evidence for alpha - and beta -phases of pure crystalline C3N4 in films deposited on nickel substrates

Cited by 82 publications

References 0 publications

Crystalline carbon nitride film synthesized by ion beam assisted magnetron sputtering and thermal annealing in nitrogen gas

Crystalline carbon nitride film synthesized by ion beam assisted magnetron sputtering and thermal annealing in nitrogen gas

NMR Chemical Shifts in Hard Carbon Nitride Compounds

Correlation between nitrogen incorporation and structural modification of hydrogenated carbon nitride films

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