First-principles study of the effect of charge on the stability of a diamond nanocluster surface

Park, Noejung; Park, Sung-Il; Hwang, Nong‐Moon; Ihm, Jisoon; Tejima, Syogo; Nakamura, Hisashi

doi:10.1103/physrevb.69.195411

Cited by 14 publications

(7 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They also confirmed that anionic charging saturates dangling bonds of carbon atoms at the surface, resulting in the disappearance of reconstructed and graphitized layers at the surface. Park et al [ 43 ] reported that negative charges stabilize the structure of nanodiamonds because the excess electrons saturate and stabilize the dangling bonds at the surface of diamond nanoparticles. If so, diamond nanoparticles generated at 1900 °C at 3% CH 4 –97% H 2 , which are relatively deficient in excess charges than those generated at 2100 °C, would mostly have the structure of i-carbon.…”

Section: Resultsmentioning

confidence: 99%

Unusual Dependence of the Diamond Growth Rate on the Methane Concentration in the Hot Filament Chemical Vapor Deposition Process

Song

Kim

et al. 2021

Materials

Self Cite

View full text Add to dashboard Cite

Although the growth rate of diamond increased with increasing methane concentration at the filament temperature of 2100 °C during a hot filament chemical vapor deposition (HFCVD), it decreased with increasing methane concentration from 1% CH4 –99% H2 to 3% CH4 –97% H2 at 1900 °C. We investigated this unusual dependence of the growth rate on the methane concentration, which might give insight into the growth mechanism of a diamond. One possibility would be that the high methane concentration increases the non-diamond phase, which is then etched faster by atomic hydrogen, resulting in a decrease in the growth rate with increasing methane concentration. At 3% CH4 –97% H2, the graphite was coated on the hot filament both at 1900 °C and 2100 °C. The graphite coating on the filament decreased the number of electrons emitted from the hot filament. The electron emission at 3% CH4 –97% H2 was 13 times less than that at 1% CH4 –99% H2 at the filament temperature of 1900 °C. The lower number of electrons at 3% CH4 –97% H2 was attributed to the formation of the non-diamond phase, which etched faster than diamond, resulting in a lower growth rate.

show abstract

Section: Resultsmentioning

confidence: 99%

Unusual Dependence of the Diamond Growth Rate on the Methane Concentration in the Hot Filament Chemical Vapor Deposition Process

Song

Kim

et al. 2021

Materials

Self Cite

View full text Add to dashboard Cite

show abstract

“…These results suggest that the electric charge stabilizes diamond over graphite. Based on a density functional calculation, Park et al [132] studied the effect of charge on the stability of a diamond nanocluster surface and showed that a negative charge stabilized diamond over graphite and a positive charge stabilized the hydrogenated surface.…”

Section: Role Of Gas Activation In the Low-pressure Synthesis Of Diamondmentioning

confidence: 99%

Charged nanoparticles in thin film and nanostructure growth by chemical vapour deposition

Hwang¹,

Lee²

2010

J. Phys. D: Appl. Phys.

Self Cite

View full text Add to dashboard Cite

The critical role of charged nanoclusters and nanoparticles in the growth of thin films and nanostructures by chemical vapour deposition (CVD) is reviewed. Advanced nanoparticle detection techniques have shown that charged gas-phase nuclei tend to be formed under conventional processing conditions of thin films and nanostructures by thermal, hot-wire and plasma CVD. The relation between gas-phase nuclei and thin film and nanostructure growth has not been clearly understood. In this review it will be shown that many films and nanostructures, which have been believed to grow by individual atoms or molecules, actually grow by the building blocks of such charged nuclei. This new growth mechanism was revealed in an attempt to explain many puzzling phenomena involved in the gas-activated diamond CVD process. Therefore, detailed thermodynamic and kinetic analyses will be made to draw the conclusion that the well-known phenomenon of deposition of less stable diamond with simultaneous etching of stable graphite should be an indication of diamond growth exclusively by charged nuclei formed in the gas phase. A similar logic was applied to the phenomenon of simultaneous deposition and etching of silicon, which also leads to the conclusion that silicon films by CVD should grow mainly by the building blocks of charged nuclei. This new mechanism of crystal growth appears to be general in many CVD and some physical vapour deposition (PVD) processes. In plasma CVD, this new mechanism has already been utilized to open a new field of plasma-aided nanofabrication.

show abstract

“…Relatively abundant electrons at 1% CH 4 -99% H 2 would tend to stabilize the sp 3 bond of nanodiamond, which would result in cubic diamond or n-diamond. On the other hand, a relative deficiency in electrons at 3% CH 4 -97% H 2 would likely induce the sp 2 bond of i-carbon [ 29 , 30 ].…”

Section: Resultsmentioning

confidence: 99%

Various Allotropes of Diamond Nanoparticles Generated in the Gas Phase during Hot Filament Chemical Vapor Deposition

Kim

et al. 2020

Nanomaterials

Self Cite

View full text Add to dashboard Cite

Diamond nanoparticles have been synthesized using various methods. Nanodiamonds generated in the gas phase were captured on the membrane of a transmission electron microscope grid during a hot filament chemical vapor deposition (HFCVD) diamond process. In total, ~600 nanoparticles, which were captured for 10 s in six conditions of the capture temperatures of 900 °C, 600 °C and 300 °C and the gas mixtures of 1% CH4-99% H2 and 3% CH4-97% H2, were analyzed for phase identification using high-resolution transmission electron microscopy and fast Fourier transformation. Hexagonal diamond, i-carbon, n-diamond, and cubic diamond were identified. The observation of two or more carbon allotropes captured on the same membrane suggested their coexistence in the gas phase during HFCVD. The crystal structure of carbon allotropes was related to the size of the nanodiamond. The crystal structure of the nanoparticles affected the crystal structure of diamond deposited for 8 h. Confirmation of various carbon allotropes provides new insight into the nanodiamond synthesis in the gas phase and the growth mechanism of HFCVD diamond.

show abstract

First-principles study of the effect of charge on the stability of a diamond nanocluster surface

Cited by 14 publications

References 39 publications

Unusual Dependence of the Diamond Growth Rate on the Methane Concentration in the Hot Filament Chemical Vapor Deposition Process

Unusual Dependence of the Diamond Growth Rate on the Methane Concentration in the Hot Filament Chemical Vapor Deposition Process

Charged nanoparticles in thin film and nanostructure growth by chemical vapour deposition

Various Allotropes of Diamond Nanoparticles Generated in the Gas Phase during Hot Filament Chemical Vapor Deposition

Contact Info

Product

Resources

About