Ultradispersed diamond powders of detonation nature for polishing X-ray mirrors

1995 ◽  
Vol 359 (1-2) ◽  
pp. 155-156 ◽  
Author(s):  
N.I. Chkhalov ◽  
M.V. Fedorchenko ◽  
E.P. Kruglyakov ◽  
A.I. Volokhov ◽  
K.S. Baraboshkin ◽  
...  
Keyword(s):  
Ultradispersed Diamond ◽  
X Ray ◽  
Diamond Powders

Particle-Assisted Oriented Deposition of Diamond Thin Films

1996 ◽  
Vol 423 ◽  
Author(s):  
Dong-Gu Lee ◽  
Rajiv K. Singh
Keyword(s):  
Vapor Deposition ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Silicon Substrates ◽  
X Ray ◽  
Diamond Particles ◽  
Film Synthesis ◽  
Diamond Powders ◽  
Hot Filament

AbstractWe have developed a method for <111> oriented diamond film synthesis using micron-sized diamond particles. Different size of diamond powders were electrophoretically seeded on silicon substrates using diamond suspensions in organic solvents (acetone, methanol, and ethanol). Diamond suspension in acetone was found to be the best for obtaining uniform diamond seeding by electrophoresis. The thickness of diamond seeded films was changed by varying the applied voltage to observe the effect on the orientation of diamond particles. Then diamond films were deposited by the hot filament chemical vapor deposition (HFCVD) process. A preferred orientation with <111> direction normal to the substrate was obtained for monolayer coatings. The surface morphology, crystal orientation, and quality of diamond films were investigated using scanning electron microscopy, x-ray diffractometry, and Raman spectroscopy.

Sintering of Compacts from Nanocrystalline Diamonds Without Sintering Agent

1997 ◽  
Vol 499 ◽  
Author(s):  
A. Witek ◽  
B. Palosz ◽  
S. Stel'Makh ◽  
S. Gierlotka ◽  
R. Pielaszek ◽  
...  
Keyword(s):  
Grain Size ◽  
High Pressure ◽  
Polycrystalline Diamond ◽  
Size Distribution Function ◽  
Nanocrystalline Powder ◽  
General Tendency ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Pressure High Temperature ◽  
Diamond Powders

ABSTRACTCompacts of polycrystalline diamond were made in toroid-type high-pressure camera under the pressure of 8 GPa using temperatures between 800 to 2150°C without the use of additive components. Nanocrystalline commercial DALAN, and microcrystalline ASM diamond powders were used. The compacts were characterized by helium pycnometry, Vickers hardness measurements, X-ray diffraction and SEM methods.The starting and sintered nanocrystalline grain compacts were found to have strongly one-dimensionally disordered cubic modification. The nanocrystalline powder had a bimodal grain size distribution function as determined from X-ray diffraction data and ab initio intensity calculations performed with the use of Debye functions. It was found that neither the grain size nor one-dimensional disordering change under high-pressure high-temperature conditions. There is a general tendency in a decrease of density of compacts with increase in the sintering temperature what resulting partly from graphitization above 1000–1200°C. The main factor which determines the density of the diamond compacts is closed porosity. Typically, the nanocrystalline diamond compacts sintered from 30 sec. to 6 min. have densities around 90% of the theoretical value. Their Vickers microhardness is 24 GPa and less.

Characterization of the structure of ultradispersed diamond using X-ray diffractometry and small-angle X-ray scattering

2014 ◽  
Vol 56 (11) ◽  
pp. 2343-2347 ◽  
Author(s):  
M. D. Sharkov ◽  
M. E. Boiko ◽  
S. N. Ivashevskaya ◽  
S. G. Konnikov
Keyword(s):  
Small Angle ◽  
Ultradispersed Diamond ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

An X-ray diffraction study of molybdenum coatings on diamond powders

1979 ◽  
Vol 18 (8) ◽  
pp. 575-577 ◽  
Author(s):  
V. G. Chuprina ◽  
G. P. Volk ◽  
I. A. Lavrinenko ◽  
Yu. V. Naidich
Keyword(s):  
Diffraction Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diamond Powders

Iron oxide nanoparticles supported on ultradispersed diamond powders: Effect of the preparation procedure

2009 ◽  
Vol 255 (7) ◽  
pp. 4322-4328 ◽  
Author(s):  
Momtchil Dimitrov ◽  
Ljubomira Ivanova ◽  
Daniela Paneva ◽  
Tanya Tsoncheva ◽  
Stavry Stavrev ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Preparation Procedure ◽  
Oxide Nanoparticles ◽  
Ultradispersed Diamond ◽  
Diamond Powders

Study of ultradispersed diamond powders obtained using explosion energy

Carbon ◽  
1991 ◽  
Vol 29 (4-5) ◽  
pp. 665-668 ◽  
Author(s):  
V.L Kuznetsov ◽  
M.N Aleksandrov ◽  
I.V Zagoruiko ◽  
A.L Chuvilin ◽  
E.M Moroz ◽  
...  
Keyword(s):  
Explosion Energy ◽  
Ultradispersed Diamond ◽  
Diamond Powders

Space and Time Distribution of Hard X-Ray Emission in a Loop at the Beginning of a Flare

1994 ◽  
Vol 144 ◽  
pp. 275-277
Author(s):  
M. Karlický ◽  
J. C. Hénoux
Keyword(s):  
Time Distribution ◽  
Electron Bombardment ◽  
Spatial Evolution ◽  
Superthermal Electrons ◽  
Flare Loop ◽  
X Ray ◽  
Superthermal Electron ◽  
Flare Loops ◽  
Chromospheric Evaporation ◽  
Temporal And Spatial

AbstractUsing a new ID hybrid model of the electron bombardment in flare loops, we study not only the evolution of densities, plasma velocities and temperatures in the loop, but also the temporal and spatial evolution of hard X-ray emission. In the present paper a continuous bombardment by electrons isotropically accelerated at the top of flare loop with a power-law injection distribution function is considered. The computations include the effects of the return-current that reduces significantly the depth of the chromospheric layer which is evaporated. The present modelling is made with superthermal electron parameters corresponding to the classical resistivity regime for an input energy flux of superthermal electrons of 109erg cm−2s−1. It was found that due to the electron bombardment the two chromospheric evaporation waves are generated at both feet of the loop and they propagate up to the top, where they collide and cause temporary density and hard X-ray enhancements.

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