Transformation of graphite into nanodiamond following extreme electronic excitations

Dunlop, A.; Jaskierowicz, G.; Ossi, P.M.; Della‐Negra, S.

doi:10.1103/physrevb.76.155403

Cited by 45 publications

(31 citation statements)

References 54 publications

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“…Many reports have discussed the effects of ion beam irradiation on the characteristics of diamond and related materials, such as type IIa diamond, 15 diamond-like carbon films, 16 taC, 17 graphite 18 and polycrystalline CVD diamond films. [19][20][21] Especially, Pandey et al 22 and Koinkar et al 23 have studied the field emission enhancement by swift heavy ion irradiation in CVD diamonds.…”

Section: Introductionmentioning

confidence: 99%

The potential application of ultra-nanocrystalline diamond films for heavy ion irradiation detection

Chen

Wang

et al. 2013

AIP Advances

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The potential of utilizing the ultra-nanocrystalline (UNCD) films for detecting the Au-ion irradiation was investigated. When the fluence for Au-ion irradiation is lower than the critical value (fc = 5.0 × 1012 ions/cm2) the turn-on field for electron field emission (EFE) process of the UNCD films decreased systematically with the increase in fluence that is correlated with the increase in sp2-bonded phase (π*-band in EELS) due to the Au-ion irradiation. The EFE properties changed irregularly, when the fluence for Au-ion irradiation exceeds this critical value. The transmission electron microscopic microstructural examinations, in conjunction with EELS spectroscopic studies, reveal that the structural change preferentially occurred in the diamond-to-Si interface for the samples experienced over critical fluence of Au-ion irradiation, viz. the crystalline SiC phase was induced in the interfacial region and the thickness of the interface decreased. These observations implied that the UNCD films could be used as irradiation detectors when the fluence for Au-ion irradiation does not exceed such a critical value

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Section: Introductionmentioning

confidence: 99%

The potential application of ultra-nanocrystalline diamond films for heavy ion irradiation detection

Chen

Wang

et al. 2013

AIP Advances

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“…These observations on shock-produced diamonds are in a good agreement with the Raman spectral properties of nanodiamonds from our Allende meteorite sample. The frequency shift may be associated with the modification of the local configuration of the sample by means of the transformation of graphite into nanodiamond (Dunlop et al 2007). In particular, the difference in frequency values for the Raman C-C bonding vibrations between 1332 and 1326 cm -1 in nanodiamond could indicate a change of the C-C bond strength caused by the phase transition at high pressure and temperature.…”

Section: Raman Frequency Shiftmentioning

confidence: 99%

Micro-Raman study of the Allende meteoritic nanodiamonds: Supernova-driven shock wave origin is revisited

Gucsik¹

2011

Central European Geology

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I have studied the Raman spectroscopic signatures of nanodiamonds from the Allende meteorite, in which some portions must be of presolar origin as indicated by the isotopic compositions of various trace elements. The spectra of the meteoritic nanodiamonds show a narrow peak at 1326 cm -1 and a broad band at 1590 cm -1 . Compared to the intensities of these peaks, the background fluorescence is relatively high. A significant frequency shift from 1332 to 1326 cm -1 , peak broadening, and appearance of a new peak at 1590 cm -1 might be due to shock effects during formation of the diamond grains. Such changes may have several origins: an increase in bond length, a change in the electron density function or charge transfer, or a combination of these factors. However, Raman spectroscopy alone does not allow distinguishing between a shock origin of the nanodiamonds and formation by a CVD process, as is favored by most workers.

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“…10,11 Moreover, many reports have discussed the effects of ion beam irradiation on the characteristics of carbon based materials such as type IIa diamond, 12 diamond-like carbon films, 13 taC, 14 graphite 15 and polycrystalline CVD diamond films. [16][17][18] Furthermore, Pandey et al 19 and Koinkar et al 20 have studied the field emission enhancement by swift heavy ion irradiation in CVD diamonds; nevertheless, the mechanism for the modification of these characteristics remains unclear.…”

Section: Introductionmentioning

confidence: 99%

Microstructure evolution and the modification of the electron field emission properties of diamond films by gigaelectron volt Au-ion irradiation

et al. 2011

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The effect of 2.245 GeV Au-ion irradiation and post-annealing processes on the microstructure and electron field emission (EFE) properties of diamond films was investigated. For the microcrystalline diamond (MCD) films, Au-ion irradiation with a fluence of approximately 8.4×1013 ions/cm2 almost completely suppressed the EFE properties of the films. Post-annealing the Au-ion irradiated MCD films at 1000°C for 1 h effectively restored these properties. In contrast, for ultra-nanocrystalline diamond (UNCD) films, the Au-ion irradiation induced a large improvement in the EFE properties, and the post-annealing process slightly degraded the EFE properties of the films. The resulting EFE behavior was still better than that of pristine UNCD films. TEM examination indicated that the difference in Au-ion irradiation/post-annealing effects on the EFE properties of the MCD and UNCD films is closely related to the different phase transformation process involved. This difference is dependent on the different granular structures of these films. The MCD films with large-grain microstructure contain very few grain boundaries of negligible thickness, whereas the UNCD films with ultra-small-grain granular structure contain abundant grain boundaries of considerable thickness. Au-ion irradiation disintegrated the large grains in the MCD films into small diamond clusters embedded in an amorphous carbon (a-C) matrix that suppressed the EFE properties of the MCD films. In contrast, the Au-ion irradiation insignificantly altered the crystallinity of the grains of the UNCD films but transformed the grain boundary phase into nano-graphite, enhancing the EFE properties. The post-annealing process recrystallized the residual a-C phase into nano-graphites for both films

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Transformation of graphite into nanodiamond following extreme electronic excitations

Cited by 45 publications

References 54 publications

The potential application of ultra-nanocrystalline diamond films for heavy ion irradiation detection

The potential application of ultra-nanocrystalline diamond films for heavy ion irradiation detection

Micro-Raman study of the Allende meteoritic nanodiamonds: Supernova-driven shock wave origin is revisited

Microstructure evolution and the modification of the electron field emission properties of diamond films by gigaelectron volt Au-ion irradiation

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