scholarly journals STRUCTURE OF POLYCRYSTALLINE DIAMOND COATINGS DEPOSITED BY СVD METHOD IN THE PLASMA OF GLOW DISCHARGE WITH THE USE OF PULSE POWER SUPPLY

2021 ◽  
pp. 113-118
Author(s):  
K.I. Koshevoy ◽  
Yu.Ya. Volkov ◽  
V.E. Strel’nitskij ◽  
E.N. Reshetnyak
Keyword(s):  
Glow Discharge ◽  
Power Supply ◽  
Natural Diamond ◽  
Polycrystalline Diamond ◽  
Lattice Parameter ◽  
Pulse Mode ◽  
Crystal Lattice Parameter ◽  
Diamond Coatings ◽  
Deposition Parameters ◽  
Diamond Crystals

The structure of CVD carbon coatings synthesized in a hydrogen-methane mixture in the plasma of a glow discharge stabilized by a magnetic field using a pulsed power supply was studied by X-ray diffraction analysis and optical microscopy. The range of deposition parameters is determined, which ensure formation of polycrystalline diamond coatings. The coatings consist of diamond crystals with a clearly defined cut and the crystal lattice parameter close to the tabular value for natural diamond. The influence of the methane partial pressure in the gas mixture and the substrate temperature on the size and predominant orientation of diamond crystals in the coatings was determined. It is established that the use of the pulse mode and grounding of the substrate holder helps to improve the quality of diamond coatings.

Effects of Various Seeding Methods on Multi-Layered Diamond Coatings Deposited via Hot Filament Chemical Vapor Deposition

2013 ◽  
Vol 845 ◽  
pp. 36-40
Author(s):  
Tze Mi Yong ◽  
Esah Hamzah
Keyword(s):  
Natural Diamond ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Columnar Structure ◽  
X Rays ◽  
Diamond Coating ◽  
Diamond Coatings ◽  
Good Adhesion ◽  
Hot Filament ◽  
Xrd Method

Multi-layer alternating nanocrystalline diamond (NCD) layer and polycrystalline diamond (PCD) layer was successfully deposited on pretreated tungsten carbide (WC) substrates with various seeding sizes (<0.1μm synthetic, <0.5μm synthetic, <0.25μm natural, <0.5μm natural, and <1μm natural) diamond with and without hammering by silicon carbide. X-rays penetrate through the coating to the substrate from XRD method was able to show strong peaks of diamond relative to WC despite the diamond film being 4μm thick only. It is found that substrates with no hammering produce stronger signals. The coating was cross sectioned and analysed using field emission scanning electron microscopy showing the multi-layer with NCD grains that has coalesced and columnar structure for PCD. None of the diamond coating delaminated during cross sectioning showing good adhesion. Raman was able to capture data from the 1-1.6μm thick NCD layer only while AFM measured the extreme low roughness of the NCD surface.

Etch-delineation of defects in diamond by exposure to an oxidizing flame

1993 ◽  
Vol 8 (6) ◽  
pp. 1217-1219 ◽  
Author(s):  
D.P. Malta ◽  
J.B. Posthill ◽  
R.A. Rudder ◽  
G.C. Hudson ◽  
R.J. Markunas
Keyword(s):  
Electron Microscopy ◽  
Defect Structure ◽  
Natural Diamond ◽  
Diamond Films ◽  
Polycrystalline Diamond ◽  
Exact Nature ◽  
Optimum Time ◽  
Diamond Crystals ◽  
Transmission Electron ◽  
Defect Sites

An experimental study of the etching properties of defects in diamond using propane flame exposure in air is presented. Both natural diamond crystals and polycrystalline diamond films were exposed to a flame for an optimum time of 3–4 s. This process topographically delineates defects in diamond via an accelerated etch rate at defect sites. Using transmission electron microscopy (TEM) to determine the exact nature and density of defects present in the diamond, we have found a direct correlation between topographical delineation observed by scanning electron microscopy (SEM) and the defect structure observed by TEM.

Structure and properties of rails after extremely long-term operation

2020 ◽  
pp. 30-39 ◽  
Author(s):  
Yu. F. Ivanov ◽  
V. E. Gromov ◽  
V. E. Kormyshev ◽  
A. M. Glezer
Keyword(s):  
Surface Layer ◽  
Lattice Parameter ◽  
Crystal Lattice Parameter ◽  
Subgrain Structure ◽  
Structure And Properties ◽  
Term Operation ◽  
Head Section ◽  
Structure Phase ◽  
Defective Surface

The paper reveals regularities and mechanisms of structure-phase states and properties formation of of differentially hardened 100-m rails of DT 350 category after the passed tonnage of 1411 mln. tons brutto. The formation of highly defective surface layer with nanosize (40–50 nm) grain-subgrain structure of pearlite colonies and submicrocrystal (150–250 nm) structure grains with structure free ferrite is detected. The change of hardness, microhardness, crystal lattice parameter, microdistorsion level, scalar and excess dislocation density on the rails head section are analyzed. The possible mechanisms of cementite plates’ transformation at extremely long-term operation are discussed.

Effect of pressure on synthetic diamond crystals at high temperatures and pressures in Fe/Ni catalyst system

CrystEngComm ◽  
2021 ◽  
Author(s):  
Shuai Fang ◽  
Yongkui Wang ◽  
Liangchao Chen ◽  
Zhiyun Lu ◽  
Zhenghao Cai ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Growth Mechanism ◽  
Synthetic Diamond ◽  
Natural Diamond ◽  
Catalyst System ◽  
Necessary Condition ◽  
Ni Catalyst ◽  
Effect Of Pressure ◽  
Diamond Crystals ◽  
System P

Pressure is a necessary condition for the growth of natural diamond. Studying the effect of pressure on the nitrogen content of diamond is important for exploring the growth mechanism of...

Peierls “Washboard” Controls Dynamics of the Domain Walls in Molecular Ferrimagnets

2015 ◽  
Vol 233-234 ◽  
pp. 55-59
Author(s):  
Marina Kirman ◽  
Artem Talantsev ◽  
Roman Morgunov
Keyword(s):  
Domain Wall ◽  
Crystal Lattice ◽  
Domain Walls ◽  
Low Frequency ◽  
Domain Wall Motion ◽  
Lattice Parameter ◽  
Structural Defects ◽  
Crystal Lattice Parameter ◽  
Wall Width ◽  
Debye Relaxation

The magnetization dynamics of metal-organic crystals has been studied in low frequency AC magnetic field. Four modes of domain wall motion (Debye relaxation, creep, slide and over - barrier motion (switching)) were distinguished in [MnII(H(R/S)-pn)(H2O)] [MnIII(CN)6]⋅2H2O crystals. Debye relaxation and creep of the domain walls are sensitive to Peierls relief configuration controlled by crystal lattice chirality. Structural defects and periodical Peierls potential compete in the damping of the domain walls. Driving factor of this competition is ratio of the domain wall width to the crystal lattice parameter.

scholarly journals The effect of antimony presence in anodic copper on kinetics and mechanism of anodic dissolution and cathodic deposition of copper

2008 ◽  
Vol 44 (1) ◽  
pp. 107-114 ◽  
Author(s):  
Z.D. Stankovic ◽  
V. Cvetkovski ◽  
M. Vukovic
Keyword(s):  
Anodic Dissolution ◽  
Single Pulse ◽  
Pulse Method ◽  
Sulfate Solution ◽  
Electrode Reaction ◽  
Xrd Analysis ◽  
Lattice Parameter ◽  
Crystal Lattice Parameter ◽  
Cathodic Deposition ◽  
Anode Copper

The influence of the presence of Sb atoms, as foreign metal atoms in anode copper, on kinetics, and, on the mechanism of anodic dissolution and cathodic deposition of copper in acidic sulfate solution has been investigated. The galvanostatic single-pulse method has been used. Results indicate that presence of Sb atoms in anode copper increase the exchange current density as determined from the Tafel analysis of the electrode reaction. It is attributed to the increase of the crystal lattice parameter determined from XRD analysis of the electrode material.

scholarly journals Polishing of Black and White CVD Grown Polycrystalline Diamond Coatings

2018 ◽  
Vol 5 (2) ◽  
pp. 50-58
Author(s):  
Snigdha Roy ◽  
Vamsi K. Balla ◽  
Awadesh K. Mallik ◽  
Victor G. Ralchenko ◽  
Andrey P. Bolshakov ◽  
...  
Keyword(s):  
Polycrystalline Diamond ◽  
Diamond Coatings ◽  
Black And White
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