scholarly journals Numerical Analysis for Impurity Effects on Diffusive-convection Flow Fields by Physical Vapor Transport under Terrestrial and Microgravity Conditions: Applications to Mercurous Chloride

2016 ◽  
Vol 27 (3) ◽  
pp. 335-341
Author(s):  
Geug Tae Kim ◽  
Moo Hyun Kwon
Keyword(s):  
Numerical Analysis ◽  
Flow Fields ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Convection Flow ◽  
Impurity Effects ◽  
Mercurous Chloride ◽  
Diffusive Convection ◽  
Microgravity Conditions

Physical vapor transport growth of mercurous chloride crystals

1993 ◽  
Vol 27 (3-4) ◽  
pp. 201-231 ◽  
Author(s):  
N.B. Singh ◽  
M. Gottlieb ◽  
R.H. Hopkins ◽  
R. Mazelsky ◽  
W.M.B. Duval ◽  
...  
Keyword(s):  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Mercurous Chloride

Kinetics of physical vapor transport at low pressure under microgravity conditions

1998 ◽  
Vol 193 (1-2) ◽  
pp. 80-89 ◽  
Author(s):  
M Piechotka ◽  
E Kaldis ◽  
G Wetzel ◽  
H.-J Schneider ◽  
W Buff ◽  
...  
Keyword(s):  
Low Pressure ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Microgravity Conditions ◽  
Kinetics Of

Convection and Diffusion Effects During Physical Vapor Transport of Hg2Cl2

1986 ◽  
Vol 87 ◽  
Author(s):  
N. B. Singh ◽  
R. H. Hopkins ◽  
R. Mazelsky ◽  
M. E. Glicksman
Keyword(s):  
Growth Rates ◽  
Vapor Transport ◽  
Microgravity Environment ◽  
Physical Vapor Transport ◽  
High Birefringence ◽  
Unidirectional Flow ◽  
Mercurous Chloride ◽  
Hydrodynamic Coupling ◽  
Rayleigh Numbers ◽  
Interfacial Convection

AbstractWe have carried out extensive experimentation on the physical vapor transport growth of mercurous chloride, which is an important material for opto-electronic devices. Because of the extraordinary combination of properties found in Hg2Cl2, including transmittance from 0.36 to 20 μm, anomalously slow soung velocity, high birefringence, and large acousto-optic diffraction efficiency, we are exploring the conditions for growth of large crystals of device quality. Our experiments have led so far to measured Hg2C12 growth rates that were orders of magnitude smaller than those expected by theories based on laminar, unidirectional flow between source and sink. Slight disturbances of the solid-vapor interface give rise to instabilities which lead to interfacial convection. This kind of convection should enhance the growth rate due to the acceleration of the materials exchange by hydrodynamic coupling, which is contrary to our findings. Interfacial convection is often connected with buoyancy-induced instabilities which dominate other instabilities under 1-g conditions. Despite attempts to reduce the Rayleigh numbers in our system, buoyancy-induced instabilities might be the cause of discrepancy between the measured and calculated growth rates. Observations of these phenomena under a microgravity environment might permit a better assessment of the transport mechanisms in physical vapor phase crystal growth of Hg2C12.

Knoop Hardness on the (0001) Plane of 4H and 6H SiC Single Crystals Fabricated by Physical Vapor Transport

2014 ◽  
Author(s):  
Jeffrey J. Swab ◽  
James W. McCauley ◽  
Brady Butler ◽  
Daniel Snoha ◽  
Donovan Harris ◽  
...  
Keyword(s):  
Single Crystals ◽  
Knoop Hardness ◽  
Vapor Transport ◽  
Physical Vapor Transport

High thermal conductivity of pure dense SiC ceramics prepared via HTPVT

2019 ◽  
Vol 12 (03) ◽  
pp. 1950032 ◽  
Author(s):  
Yuchen Deng ◽  
Yaming Zhang ◽  
Nanlong Zhang ◽  
Qiang Zhi ◽  
Bo Wang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Silicon Carbide ◽  
Grain Size ◽  
Phase Composition ◽  
Room Temperature ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Growth Substrate ◽  
Sic Ceramics ◽  
Evolution Of Microstructure

Pure dense silicon carbide (SiC) ceramics were obtained via the high-temperature physical vapor transport (HTPVT) method using graphite paper as the growth substrate. The phase composition, the evolution of microstructure, the thermal diffusivity and thermal conductivity at RT to 200∘C were investigated. The obtained samples had a relative density of higher than 98.7% and a large grain size of 1[Formula: see text]mm, the samples also had a room-temperature thermal conductivity of [Formula: see text] and with the temperature increased to 200∘C, the thermal conductivity still maintained at [Formula: see text].

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