scholarly journals The Influence of B, N and Si Doping on the CH3 Adsorption on the Diamond Surface Based on DFT Calculations

Crystals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 427 ◽  
Author(s):  
Liang Wang ◽  
Jiangshan Liu ◽  
Tang Tang
Keyword(s):  
Adsorption Energy ◽  
Density Functional ◽  
Valence Electron ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Diamond Surface ◽  
Silicon Doping ◽  
Valence Electron Structure ◽  
Calculation Results ◽  
Cvd Diamond Film

To better understand the influence mechanism of boron, nitrogen and silicon dopants on the growth of chemical vapor deposition (CVD) diamond film, density functional calculations have been performed to reveal the different impact of the impurities on the CH3 adsorption on diamond surface. The substituted doping and radical doping of diamond (111) and (100) − 2 × 1 surface are both considered. The calculation results indicate that the CH3 radicals are hardly adsorbed on nitrogen atoms and thus may cause vacancy in the diamond lattice easily. Boron substituted doping will disfavor the adsorption of CH3 due to the lacking of valence electron. However, the empty p orbitals of boron atom will help the chemical adsorbing of CH3 radicals. The substituted silicon doping has little influence on the CH3 adsorption, as Si atom has the same outer valence electron structure with C atom. In the case of radical doping, the adsorption energy of CH3 will be reduced due to the steric hindrance between NH2 or SiH3 with CH3. The adsorption energy can be slightly enhanced when BH2 radical is pre-adsorbed on diamond (111) surface. However, the BH2 pre-adsorbed on diamond (100) − 2 × 1 surface may interact with surface radical carbon site and result in a large reduction of CH3 adsorption energy. Thus, the boron doping may hinder the formation of the (100) facet during the CVD diamond deposition under a certain condition.

The Performance of Plasma and Multi-Physical Fields in DC Arc Plasma Reactor for CVD Diamond Film

2016 ◽  
Vol 852 ◽  
pp. 1140-1146
Author(s):  
Xiao Jing Li ◽  
Yong Liang Gao ◽  
Yan Yin ◽  
Shun Qi Zheng ◽  
Yang Sheng Zheng
Keyword(s):  
Diamond Film ◽  
Gas Flow ◽  
Plasma Reactor ◽  
Plasma Temperature ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Arc Plasma ◽  
Cvd Diamond Film ◽  
Physical Fields ◽  
Dc Arc

Numerical simulation method was developed to investigate the performance of plasma and multi-physical fields in direct current (DC) arc plasma reactor for chemical vapor deposition (CVD) Diamond film,in order to obtain more information on the process of CVD. Finite Volume Method (FVM) was adopted. Continuous arc forming and the dynamic formation process of rotating arc plasma were shown in this paper. Multi-physics field in deposition chamber were modeled including flow field, temperature field. Distribution of velocity and temperature were obtained by solving momentum and energy equation with SIMPLE separation algorithm. Simulation results show that, plasma temperature near the cathode tip is the highest, which is more than 1×104K. The plasma distribution shape like the bell jar. The changing regularity of outlet velocity, temperature and static pressure with the distance from the anode center were revealed. The effectiveness of plasma temperature and gas flow calculated was confirmed by the experimental results. The research results provide the theoretical foundation for obtaining uniform diamond thick film.

Electrical Properties in Cvd Diamond Films

1993 ◽  
Vol 302 ◽  
Author(s):  
S. Zhao ◽  
K.K. Gan ◽  
H. Kagan ◽  
R. Kass ◽  
R. Malchow ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Carrier Mobility ◽  
Average Distance ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Time Resolved ◽  
Chemical Vapor Deposited ◽  
Natural Type ◽  
Cvd Diamond Film

ABSTRACTThe electrical properties associated with carrier mobility, μ, and lifetime, τ, have been investigated for the chemical vapor deposited (CVD) diamond films using charged particle-induced conductivity and time resolved transient photo-induced conductivity. The collection distance, d, the average distance which electron and hole depart when driven by an applied electric field E, was measured by both methods. The collection distance is related to the carrier mobility and lifetime by d = μEτ Our measurements show that the collection distance increases linearly with sample thickness for CVD diamond films. The collection distance at the growth side of the CVD diamond film is comparable to that of single crystal natural type IIa diamond; at the substrate side of the film, the collection distance is near zero. No saturation of the collection distance is observed for film thickness up to 500 microns.

Direct Measurement of the Adhesive Fracture Resistance of CVD Diamond Particles

1998 ◽  
Vol 120 (4) ◽  
pp. 367-371 ◽  
Author(s):  
S. Kamiya ◽  
H. Takahashi ◽  
M. Saka ◽  
H. Abe´
Keyword(s):  
Adhesive Strength ◽  
Diamond Film ◽  
Fracture Resistance ◽  
Early Stage ◽  
Chemical Vapor ◽  
Maximum Load ◽  
Cvd Diamond ◽  
Adhesive Fracture ◽  
Diamond Particles ◽  
Cvd Diamond Film

Diamond film produced by chemical vapor deposition (CVD) is being used in the electronics industry because of their excellent properties. In order to measure the adhesive strength of CVD diamond, external load is directly applied in a scanning electron microscope to the CVD diamond particles that sparsely appear on silicon substrate in the early stage of deposition. These particles are called nuclei when they are small and grow into contact with each other to form polycrystalline CVD diamond film. Diamond film was supposed to adhere to the substrate at only these discrete nucleation points, which might result in weak adhesive strength. We measure the maximum load, as the adhesive fracture resistance, required to scratch off the particles with 2–13 μm diameter. Adhesive fracture resistance is found to increase with the diameter of the particle. Hence we conclude that CVD diamond does not adhere only at the nucleation points but that the whole contact area to the substrate is responsible for its adhesive strength.

Study on the Precipitated Behavior and Stability of the Strengthening Phase Al12(Fe,X)3Si in Al-Fe-Si-X Alloys with the EET Theory

2010 ◽  
Vol 152-153 ◽  
pp. 743-747
Author(s):  
Hua Qu ◽  
Wei Dong Liu ◽  
Gang Zhou ◽  
Xiao Lu Shen ◽  
Chuang Liu
Keyword(s):  
Valence Electron ◽  
Electron Structure ◽  
Alloying Elements ◽  
Strengthening Phase ◽  
Alloying Element ◽  
Valence Electron Structure ◽  
Empirical Electron Theory ◽  
Calculation Results ◽  
The Stability ◽  
State Group

According to the empirical electron theory of solid and molecule, the effects of alloying elements on the valence electron structure, precipitated behavior and stability of Al12Fe3Si were studied in this paper. The calculation results show that the adding of V, Cr, W, Mo and Mn change the valence electron structure of Al12Fe3Si, and make its number of atom state group N increased by 2 orders of magnitude, so it make the stability of the alloy increased and then delay the coarsening speed; the adding of alloying element makes the total ability of forming bond F reduced and accelerates the precipitated of Al12Fe3Si and make it refined; the order for the adding of the alloying elements V, Cr, W, Mo and Mn of the effects on stability of Al12Fe3Si is Cr(Mn)→W(Mo)→V, and that of accelerating the dispersion precipitated of Al12Fe3Si is Cr→V→Mo→W→Mn; when practicing to design Al-Fe-Si-X alloy, we can obtain it through controlling the ratio of Fe/X to refine the particles of Al12(Fe,X)3Si, therefore, its stability can be improved and its coarsening can be delayed.

DENSITY FUNCTIONAL THEORY STUDIES ON THE ADSORPTION OF 4-METHYLBENZENETHIOL AND 4-ETHYLBENZENETHIOL MOLECULES ON Au(111) SURFACE

2014 ◽  
Vol 21 (06) ◽  
pp. 1450087 ◽  
Author(s):  
XIAOLIANG FANG ◽  
XIAOLI FAN ◽  
RUNXIN RAN ◽  
PIN XIAO
Keyword(s):  
Density Functional Theory ◽  
Tilt Angle ◽  
Adsorption Energy ◽  
First Principles ◽  
Density Functional ◽  
Energy Calculation ◽  
Functional Theory ◽  
Calculation Results ◽  
Adsorption Energies ◽  
First Principles Method

The nondissociative and dissociated adsorptions of 4-methylbenzenethiol (4-MBT) and 4-ethylbenzenethiol (4-EBT) on Au (111) surface were studied by applying the first-principles method based on density functional theory. The effects of coverage and vdW interactions on adsorptions were investigated. Adsorption energies and tilt angles of both 4-MBT and 4-EBT decrease with the increase of the coverage, and vdW interactions can affect the adsorption configuration and energy. More importantly, in the case of 4-EBT adsorption, we have studied the effects of ethyl group's orientation on the adsorption configuration and energy. Calculation results show that ethyl group's orientation has little effect on the adsorption energy, but changes the tilt angle by around 7°. Our calculations provide a deeper elucidation of the observed adsorption configuration for 4-EBT on Au (111).

Deposition and Application of CVD Diamond Film on the Interior-Hole Surface of Shaped-Wire Drawing Die

2012 ◽  
Vol 217-219 ◽  
pp. 1022-1027
Author(s):  
Liu Jin Bian ◽  
Zi Chao Lin ◽  
Fang Hong Sun ◽  
Song Shou Guo
Keyword(s):  
Surface Quality ◽  
Diamond Film ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Wire Drawing ◽  
Drawing Die ◽  
Before And After ◽  
Cvd Diamond Film ◽  
Drawing Dies

Abstract：The shaped-wire drawing dies are used more and more popularly in the metal product industry for several advantages of locked structure. In present investigation, a layer of CVD diamond film is deposited on the interior-hole surface of shaped-wire drawing die using a hot filament chemical vapor deposition (HFCVD) method, followed by a surface polishing process, aiming at further prolonging its working lifetime of shaped-wire drawing dies and improving the surface quality of produced wires. The scanning electron microscopy (SEM), surface profiler and Raman spectroscopy are adopted to present the characterization of both as-deposited CVD diamond films before and after polishing. Furthermore, the performance of as-fabricated CVD diamond coated drawing dies is examined in the practical production process. The results show that as-deposited CVD diamond films are homogeneous and the working surface is smoother after polishing. Comparing with the conventional shaped drawing dies, the working lifetime of the diamond coated shaped-wire drawing dies can be increased by a factor of above 10, and the shaped wires with higher surface quality can be obtained.

Study on the Surface Integrity of Polished Diamond Thick Film Prepared by EACVD

2007 ◽  
Vol 359-360 ◽  
pp. 319-323
Author(s):  
Feng Xu ◽  
Dun Wen Zuo ◽  
Rong Fa Chen ◽  
Wen Zhuang Lu ◽  
Min Wang
Keyword(s):  
Surface Roughness ◽  
Thick Film ◽  
Surface Integrity ◽  
Diamond Film ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Cvd Diamond ◽  
Deformation Energy ◽  
Polished Surface ◽  
Cvd Diamond Film

Chemical vapor deposited (CVD) diamond film is a good materials for cutting tools as its a series of excellent properties. But because of its polycrystalline morphology, CVD diamond thick film has a rough surface that limits its application in engineering. In this paper, study was carried out on the mechanical lapping of diamond film. It is shown that surface roughness of the film was reduced from Ra 4.5μm to Ra 0.2μm after 50-minute polishing. The surface integrity of polished diamond thick film was investigated, which includes surface roughness, morphology and residual stress. There are a lot of micro defects such as grooves, gas cavities and micro cracks on the polished surface, which are the intrinsic defects generated in the deposition process of CVD diamond film. The tensile stress of the film reduced through polishing as the release of the deformation energy stored in the film.

Effect of Oxygen on CVD Diamond Film Deposition

2012 ◽  
Vol 482-484 ◽  
pp. 891-894
Author(s):  
Yuan Sheng Huang ◽  
Cheng Ping Luo ◽  
Wan Qi Qiu
Keyword(s):  
Oxygen Content ◽  
Vapor Deposition ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Film Deposition ◽  
Chemical Vapor Deposition Method ◽  
Deposition Method ◽  
Cvd Diamond Film ◽  
Effect Of Oxygen

CVD diamond films were synthesized by the chemical vapor deposition method. With increasing the oxygen content in the deposition atmosphere, the density of diamond nuclei decreases. No diamond is formed when the oxygen content is more than one percent. The density of diamond nuclei is improved with increasing the methane content. Adding oxygen to the deposition atmosphere can enhance the purity of diamond.

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