Synthesis and characterization of diamonds with different nitrogen concentrations under high pressure and high temperature conditions

Chen, Liangchao; Miao, Xiao; Ma, Hongan; Guo, Longsuo; Wang, Zhanke; Yang, Zhiqiang; Fang, Chao; Jia, Xiaopeng

doi:10.1039/c8ce01533c

Cited by 58 publications

(34 citation statements)

References 39 publications

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“…The disappearance of NV − centres and multivacancies has previously been observed [31] after sintering detonation nanodiamonds at HPHT conditions (P = 7 GPa and T ≥ 1350 °C) with ethanol. 8 The presence of multivacancies is a characteristic feature of damaged diamond lattices, with defects mainly located in a thin layer of ~ 2 nm at the surface. The absence of the paramagnetic triplet and SiV colour centres is strong evidence that substantial recrystallisation took place, accompanied with the appearance of new defect types (NVN).…”

Section: Discussionmentioning

confidence: 99%

“…7 Optoelectronics and Measurement Techniques Research Unit, University of Oulu, 90570 Oulu, Finland. 8 Microdiamant AG, Kreuzlingerstrasse 1, 8574 Lengwil, Switzerland.…”

Section: Acknowledgementsmentioning

confidence: 99%

“…However, in recent years various non-conventional metal catalysts have begun to be widely used [6]. Such a method allows the use of nitrogen-containing organic additives and metal getters to controllably dope diamond across a range from high nitrogen content (up to ~ 1000 ppm), down to a much lower level (~ 50 ppm) [7,8]. HPHT is also used to anneal diamond crystals and improve their crystalline quality, to decolour them, and to sinter nanocrystals into larger polycrystals.…”

Section: Introductionmentioning

confidence: 99%

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High-Quality Green-Emitting Nanodiamonds Fabricated by HPHT Sintering of Polycrystalline Shockwave Diamonds

et al. 2020

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We demonstrate a high-pressure, high-temperature sintering technique to form nitrogen-vacancy-nitrogen centres in nanodiamonds. Polycrystalline diamond nanoparticle precursors, with mean size of 25 nm, are produced by the shock wave from an explosion. These nanoparticles are sintered in the presence of ethanol, at a pressure of 7 GPa and temperature of 1300 °C, to produce substantially larger (3–4 times) diamond crystallites. The recorded spectral properties demonstrate the improved crystalline quality. The types of defects present are also observed to change; the characteristic spectral features of nitrogen-vacancy and silicon-vacancy centres present for the precursor material disappear. Two new characteristic features appear: (1) paramagnetic substitutional nitrogen (P1 centres with spin ½) with an electron paramagnetic resonance characteristic triplet hyperfine structure due to the I = 1 magnetic moment of the nitrogen nuclear spin and (2) the green spectral photoluminescence signature of the nitrogen-vacancy-nitrogen centres. This production method is a strong alternative to conventional high-energy particle beam irradiation. It can be used to easily produce purely green fluorescing nanodiamonds with advantageous properties for optical biolabelling applications.

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Section: Discussionmentioning

confidence: 99%

“…7 Optoelectronics and Measurement Techniques Research Unit, University of Oulu, 90570 Oulu, Finland. 8 Microdiamant AG, Kreuzlingerstrasse 1, 8574 Lengwil, Switzerland.…”

Section: Acknowledgementsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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High-Quality Green-Emitting Nanodiamonds Fabricated by HPHT Sintering of Polycrystalline Shockwave Diamonds

et al. 2020

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“…Also, the vacancies and N-related defects create deep energy levels within the forbidden energy gap and each such defect (known as color centers) emits photons at characteristic wavelength under suitable excitation. Thus, many investigations report on the identification of N induced point defects and N-related complex defects in diamonds through optical spectroscopic studies [22,23,24,25,26,27,28,29,30]…”

Section: Introductionmentioning

confidence: 99%

Structural, Raman and photoluminescence studies on nanocrystalline diamond films: Effects of ammonia in feedstock

Ganesan¹,

Ajikumar²,

Srivastava³

et al. 2020

Diamond and Related Materials

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Herein, we report on the improvement of structural quality and enhancement of photoluminescence (PL) emission for an optimally N doped nanocrystalline diamond (NCD) film.Pure and N doped nanocrystalline diamond films are synthesized on Si by hot filament chemical vapour deposition using NH3:CH4:H2 at different nominal N/C ratios viz. 0, 0.13, 0.35, 0.50 and 0.75 in feedstock. X-ray diffraction analysis reveal a systematic initial increase and then a decrease in crystallite size with N/C ratio in feedstock. Further, a monotonic increase in Raman line width and peak position of diamond band indicates that the compressive strain in diamond lattice increases as a function of N/C ratio upto 0.50. However, at higher N/C ratio of 0.75, the compressive strain gets relaxed a little and produces a lower strain. Furthermore, a unique Raman mode at 1195 cm -1 is observed corresponding to the C=N-H vibrations indicating a significant N concentration in the NCD films. In addition, visible and UV PL studies reveal the presence of several N-related colour centres with multiple emission lines in the range of 380 -700 nm. An optimally N doped diamond film grown at N/C ratio of 0.35 in feedstock shows a significant enhancement in room temperature PL emission at ~ 505 and 700 nm. This PL enhancement is attributed to H3 and other aggregates of N related defect centres, under 355 and 532 nm laser excitations respectively.

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“…Diamond coatings have been commercialized with steady growth of their market. Although there are many methods to deposit diamonds, the most widely used one would be hot filament chemical vapor deposition (HFCVD) [4][5][6][7]. Diamond coatings by HFCVD have many advantages such as low cost and mass production.…”

Section: Introductionmentioning

confidence: 99%

Formation of Pentagonal Dimples in Icosahedral Diamond Crystals Grown by Hot Filament Chemical Vapor Deposition: Approach by Non-Classical Crystallization

et al. 2019

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In this study, acetone was used as a carbon source to deposit diamond films using tantalum filaments by hot filament chemical vapor deposition (HFCVD). For acetone fluxes of 80, 90, 130 and 170 standard cubic centimeters per min (sccm) and the respective hydrogen fluxes of 420, 410, 370, and 330 sccm, film thickness appeared to increase with increasing acetone, and high quality diamonds were deposited with well-defined facets of (111) and (100). For acetone fluxes of 210 and 250 sccm and the respective hydrogen fluxes of 290 and 250 sccm, however, the diamond quality was degraded with cauliflower-shaped structures evolving and the film thickness decreased with increasing acetone. The degradation of diamond quality was confirmed by Raman spectra and X-ray diffraction (XRD). Many diamond crystals grown at acetone fluxes of 80, 90, 130 and 170 sccm consisted of five (111) facets, indicating an icosahedral structure. At the corner where the five (111) facets met, there were pentagonal dimples, which implied that diamond crystals must have been etched. The decrease in film thickness at high acetone fluxes of 210 and 250 sccm also implied that the deposited film must have been etched. These results indicate that the two irreversible processes of deposition and etching occur simultaneously, which would violate the second law of thermodynamics from the classical concept of crystal growth by an individual atom. These puzzling results could be successfully explained by non-classical crystallization, where the building blocks for diamond films are nanoparticles formed in the gas phase.

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Synthesis and characterization of diamonds with different nitrogen concentrations under high pressure and high temperature conditions

Abstract: In this study, {111}-oriented diamond crystals with different nitrogen concentrations were successfully synthesized in a series of experiments at 5.8 GPa pressure and 1380–1400 °C temperature.

Cited by 58 publications

References 39 publications

High-Quality Green-Emitting Nanodiamonds Fabricated by HPHT Sintering of Polycrystalline Shockwave Diamonds

High-Quality Green-Emitting Nanodiamonds Fabricated by HPHT Sintering of Polycrystalline Shockwave Diamonds

Structural, Raman and photoluminescence studies on nanocrystalline diamond films: Effects of ammonia in feedstock

Formation of Pentagonal Dimples in Icosahedral Diamond Crystals Grown by Hot Filament Chemical Vapor Deposition: Approach by Non-Classical Crystallization

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