Diamond Needles And Tips As Engineered Growth Shapes

1995 ◽  
Vol 416 ◽  
Author(s):  
K. A. Cherian ◽  
J. Litster ◽  
V. Rudolph ◽  
E. T. White
Keyword(s):  
Vapour Phase ◽  
Nucleation And Growth ◽  
Crystallographic Direction ◽  
Spiral Growth ◽  
Diamond Growth ◽  
Nucleation Density ◽  
Diamond Nucleation ◽  
Practical Applications ◽  
Nucleation Sites ◽  
Double Spiral

ABSTRACTDiamond nucleation and growth by CFD were investigated to examine the possibility of engineering diamond growth shapes for practical applications. The results obtained include the following:a) Evidence supporting certain factors influencing nucleation - useful in controlling nucleation sites and nucleation density.b) Evidence for a double spiral growth mechanism operating on (111) faces under specific conditions - indicates the possibility of a new mechanism operating for diamond growth from the vapour phase, and the possibility of larger growth rates.c) Evidence for the enhanced growth in <100= crystallographic direction on a cubooctahedral crystal and its control by varying the process parameters – thus showing the possibility of obtaining diamond needles and tips as engineered growth shapes, for specific applications.

The Effects of Chloromethane on Diamond Nucleation and Growth in a Hot-filament Chemical Vapor Deposition Reactor

1998 ◽  
Vol 13 (9) ◽  
pp. 2498-2504 ◽  
Author(s):  
Jih-Jen Wu ◽  
Franklin Chau-Nan Hong
Keyword(s):  
Film Growth ◽  
Chemical Vapor ◽  
Nucleation And Growth ◽  
Diamond Growth ◽  
Nucleation Density ◽  
Diamond Grit ◽  
Diamond Nucleation ◽  
Nucleation Sites ◽  
Lower Temperature ◽  
Hot Filament

The effects of chloromethane on diamond nucleation and growth were studied by employing laser reflective interferometry. Chloromethane enhances the film-growth rate only slightly compared to methane. However, chloromethane greatly enhances the nucleation density and shortens the film-forming stage, more significantly at a lower temperature. Thus, chloromethane facilitates the low temperature growth mainly through the enhancement of nucleation. Nucleation density is strongly dependent on the compositions of H atoms and carbon species prior to diamond growth. The residual diamond seeds by diamond-grit scratching are suggested to be the major nucleation sites. Chloromethane can enhance diamond nucleation by protecting the residual seeds from being etched by H atoms.

Diamond growth on carbide surfaces using a selective etching technique

1994 ◽  
Vol 9 (8) ◽  
pp. 2154-2163 ◽  
Author(s):  
K.J. Grannen ◽  
R.P.H. Chang
Keyword(s):  
Vapor Deposition ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Diamond Powder ◽  
Nucleation And Growth ◽  
Diamond Growth ◽  
Etching Technique ◽  
Diamond Nucleation ◽  
Nucleation And Growth Mechanism

Microwave plasma-enhanced chemical vapor deposition of diamond films on silicon carbide and tungsten carbide (with 6% cobalt) surfaces using fluorocarbon gases has been demonstrated. No diamond powder pretreatment is necessary to grow these films with a (100) faceted surface morphology. The diamond films are characterized by scanning electron microscopy and Raman spectroscopy. The proposed nucleation and growth mechanism involves etching of the noncarbon component of the carbide by atomic fluorine to expose surface carbon atoms and diamond nucleation and growth on these exposed carbon atoms. Hydrogen is necessary in the growth process to limit the rapid etching of the carbide substrates by corrosive fluorine atoms.

Effects of secondary pretreatments of substrate on the nucleation of diamond film

1996 ◽  
Vol 11 (7) ◽  
pp. 1787-1794 ◽  
Author(s):  
W. S. Yang ◽  
Jung Ho Je
Keyword(s):  
Plasma Etching ◽  
Chemical Etching ◽  
Diamond Powder ◽  
Structural Defects ◽  
Nucleation Density ◽  
Diamond Nucleation ◽  
Si Substrates ◽  
Nucleation Sites ◽  
Wet Chemical ◽  
Wet Chemical Etching

The effects of secondary pretreatments on diamond nucleation were investigated for the Si substrates pretreated by the diamond abrasion. When the substrate was just abraded with diamond powder, the nucleation density of diamond was 7 × 108/cm2. However, the nucleation density was found to be greatly decreased by various secondary pretreatments except by one wet chemical etching method. The nucleation density was reduced to 3 × 107/cm2 by the chemical etching (I), to 7 × 106/cm2 by the H2 plasma etching, and to ∼104/cm2 by the Ar sputtering, or O2 plasma etching. It was very slightly reduced to 3 × 108/cm2 by the chemical etching (II). The effects of secondary pretreatments in reducing the nucleation density were found to be very closely related to the removal of diamond seeds rather than topographic sites or structural defects. Therefore, diamond seeds generated by the diamond abrasion are considered as the main nucleation sites of diamond.

Enhanced nucleation density of chemical vapor deposition diamonds by using interlayer

1997 ◽  
Vol 12 (3) ◽  
pp. 657-664 ◽  
Author(s):  
J. J. Lee ◽  
W. S. Yang ◽  
Jung Ho Je
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Rf Sputtering ◽  
Chemical Vapor ◽  
Diamond Growth ◽  
Nucleation Density ◽  
Plasma Chemical Vapor Deposition ◽  
Si Substrates ◽  
Nucleation Sites

Effects of interlayers on diamond nucleation were investigated for the Si substrates. Interlayers were deposited on the diamond-abraded Si substrates by rf sputtering prior to diamond growth using microwave plasma chemical vapor deposition (CVD). Compared with 1 × 108/cm2 for the just abraded substrate, the nucleation density was greatly enhanced to 1 ∼ 2 × 109/cm2 by 50 nm thick interlayer, irrespective of the kind of interlayer material used in this study (Si, Mo, Ti, Pt, Ag, TiN, or SiO2). As the thickness of the Si interlayer increased from 20 to 500 nm, the nucleation density reached a maximum value, 3 × 109/cm2 at 100 nm. However, the growth rate was monotonically reduced from ∼300 nm/h to ∼100 nm/h. For the 700 nm thick Si interlayer, no diamond growth was observed. These results indicate that there is an optimum interlayer thickness around 100 nm for the higher nucleation density. The role of the interlayer in enhancing the nucleation density is believed to protect the nucleation sites generated by the diamond abrasion, otherwise they could be considerably etched away by atomic hydrogen during the initial diamond deposition.

Nucleation and growth of diamond on carbon-implanted single crystal copper surfaces

1992 ◽  
Vol 7 (9) ◽  
pp. 2429-2439 ◽  
Author(s):  
T.P. Ong ◽  
Fulin Xiong ◽  
R.P.H. Chang ◽  
C.W. White
Keyword(s):  
Single Crystal ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Copper Surface ◽  
Nucleation And Growth ◽  
Diamond Growth ◽  
Diamond Nucleation ◽  
Copper Surfaces ◽  
Single Crystal Copper ◽  
Graphite Film

The nucleation and growth of diamond crystals on single crystal copper surfaces has been studied. Microwave plasma enhanced chemical vapor deposition (MPECVD) was used for diamond nucleation and growth. Prior to diamond nucleation, the single crystal copper surface is modified by carbon ion implantation at an elevated temperature (∊820 °C). This procedure leads to the formation of a graphite film on the copper surface, resulting in an enhancement of diamond crystallite nucleation. A simple lattice model has been constructed to describe the mechanism of diamond nucleation on graphite as 〈111〉diamond parallel to 〈0001〉graphite and 〈110〉diamond parallel to 〈11$\overline 1$0〉graphite. This leads to a good understanding of diamond growth on carbon-implanted copper surfaces.

Seed-Free Growth of Diamond Patterns on Femtosecond Laser Processed Silicon Substrates

2013 ◽  
Vol 1511 ◽  
Author(s):  
Mengmeng Wang ◽  
Yunshen Zhou ◽  
Z. Q. Xie ◽  
Y. Gao ◽  
Lan Jiang ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Femtosecond Laser ◽  
Femtosecond Lasers ◽  
Peak Position ◽  
Quality Parameter ◽  
Diamond Growth ◽  
Nucleation Density ◽  
Silicon Substrates ◽  
Diamond Nucleation ◽  
Growth Method

ABSTRACTDue to its outstanding properties, diamond is considered as an ideal material for mechanical and electric applications at high temperatures, voltages, radiation, etc. It is known that femtosecond lasers exhibit extremely high precision and minimized thermal effect in material processing. In this study, a seed-free diamond pattern growth method was developed by patterning silicon substrates using a femtosecond laser before diamond deposition through laser-assisted combustion flame synthesis. The resolution of the diamond patterns reaches micro scales. Peak position, full width at half maximum (FWHM), and diamond quality parameter were calculated from Raman spectra. The mechanism of the seed-free diamond growth based on the femtosecond laser patterning was discussed. The influence of substrates surface roughness on the diamond nucleation and subsequent growth was studied, indicating that the nucleation density is proportional to the surface roughness.

The effects of Methane Concentration on diamond nucleation and growth during bias enhanced nucleation on 3C-SiC(100) surfaces

2006 ◽  
Vol 956 ◽  
Author(s):  
Jean-Charles Arnault ◽  
Samuel Saada ◽  
Luciana Intiso ◽  
Philippe Bergonzo
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Methane Concentration ◽  
Nucleation And Growth ◽  
Nucleation Density ◽  
Growth Mechanisms ◽  
Diamond Nucleation ◽  
Density Values ◽  
Nucleation And Growth Mechanisms ◽  
Scanning Electron

ABSTRACTThe methane effects on nucleation and growth of diamond during bias enhanced nucleation treatment have been studied on 3C-SiC (100) surfaces. At low methane concentration of 1%, no diamond nucleation was observed, whether at 3 %, nucleation density values as high as 4×1010/cm2 were reached. A further increase of the methane concentration up to 5% induces a significant enhancement of the diamond nucleation density that was observed only slightly higher at 7×1010/cm2. Moreover, the Field Emission Gun Scanning Electron Microscopy (FEG-SEM) pictures well emphasized that the methane content affects both the nucleation and growth mechanisms.

scholarly journals Towards practical applications of quantum emitters in boron nitride

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Koperski ◽  
K. Pakuła ◽  
K. Nogajewski ◽  
A. K. Dąbrowska ◽  
M. Tokarczyk ◽  
...  
Keyword(s):  
Optical Properties ◽  
Boron Nitride ◽  
Vapour Phase ◽  
Emission Characteristics ◽  
Vapour Phase Epitaxy ◽  
Practical Applications ◽  
Metalorganic Vapour Phase Epitaxy ◽  
Polydimethylsiloxane Films ◽  
Background Luminescence ◽  
Quantum Emitters

AbstractWe demonstrate quantum emission capabilities from boron nitride structures which are relevant for practical applications and can be seamlessly integrated into a variety of heterostructures and devices. First, the optical properties of polycrystalline BN films grown by metalorganic vapour-phase epitaxy are inspected. We observe that these specimens display an antibunching in the second-order correlation functions, if the broadband background luminescence is properly controlled. Furthermore, the feasibility to use flexible and transparent substrates to support hBN crystals that host quantum emitters is explored. We characterise hBN powders deposited onto polydimethylsiloxane films, which display quantum emission characteristics in ambient environmental conditions.

Kinetic Monte Carlo Simulation of Impurity Effects on Nucleation and Growth of SiC Clusters on Si(100)

2013 ◽  
Vol 740-742 ◽  
pp. 393-396
Author(s):  
Maxim N. Lubov ◽  
Jörg Pezoldt ◽  
Yuri V. Trushin
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Cluster Size ◽  
Kinetic Monte Carlo ◽  
Nucleation And Growth ◽  
Nucleation Density ◽  
Nucleation Process ◽  
Impurity Effects ◽  
Kinetic Monte Carlo Simulations ◽  
The Mean

The influence of attractive and repulsive impurities on the nucleation process of the SiC clusters on Si(100) surface was investigated. Kinetic Monte Carlo simulations of the SiC clusters growth show that that increase of the impurity concentration (both attractive and repulsive) leads to decrease of the mean cluster size and rise of the nucleation density of the clusters.

scholarly journals N-Dopant-Mediated Growth of Metal Oxide Nanoparticles on Carbon Nanotubes

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1882
Author(s):  
Jin Ah Lee ◽  
Won Jun Lee ◽  
Joonwon Lim ◽  
Sang Ouk Kim
Keyword(s):  
Carbon Nanotubes ◽  
Metal Oxide ◽  
Carbon Nanomaterials ◽  
Wide Spectrum ◽  
Metal Oxide Nanoparticles ◽  
Nucleation And Growth ◽  
Oxide Nanoparticles ◽  
Metal Oxide Nanoparticle ◽  
Nucleation Sites ◽  
Direct Growth

Metal oxide nanoparticles supported on heteroatom-doped graphitic surfaces have been pursued for several decades for a wide spectrum of applications. Despite extensive research on functional metal oxide nanoparticle/doped carbon nanomaterial hybrids, the role of the heteroatom dopant in the hybridization process of doped carbon nanomaterials has been overlooked. Here, the direct growth of MnOx and RuOx nanoparticles in nitrogen (N)-doped sites of carbon nanotubes (NCNTs) is presented. The quaternary nitrogen (NQ) sites of CNTs actively participate in the nucleation and growth of the metal nanoparticles. The evenly distributed NQ nucleation sites mediate the generation of uniformly dispersed <10 nm diameter MnOx and RuOx nanoparticles, directly decorated on NCNT surfaces. The electrochemical performance of the resultant hybridized materials was evaluated using cyclic voltammetry. This novel hybridization method using the dopant-mediated nucleation and growth of metal oxides suggests ways that heteroatom dopants can be utilized to optimize the structure, interface and corresponding properties of graphitic carbon-based hybrid materials.

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