High thermal conductivity of pure dense SiC ceramics prepared via HTPVT

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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Effect of Initial Alpha-SiC Content on Thermal Conductivity of Silicon Carbide Ceramics

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.616.23 ◽

2014 ◽

Vol 616 ◽

pp. 23-26 ◽

Cited By ~ 2

Author(s):

Kwang Young Lim ◽

Tae Young Cho ◽

Young Wook Kim ◽

Seung Jae Lee

Keyword(s):

Thermal Conductivity ◽

Grain Size ◽

Room Temperature ◽

Phase Content ◽

Sic Ceramics ◽

Α Phase ◽

Average Grain Size ◽

Carbide Ceramics ◽

Equiaxed Grains ◽

Silicon Carbide Ceramics

By using α-and/or β-SiC powders, the effects of initial α-phase content on the microstructure and thermal properties of the SiC ceramics sintered with Y2O3 and Sc2O3 were investigated. When α-SiC powder was used, the microstructure consisted of large equiaxed grains and small equiaxed grains. The average grain size decreased with increasing α-SiC content in the starting composition. The thermal conductivity decreased with increasing α-SiC content in the starting composition. Such results suggest that the grain growth of SiC ceramics is beneficial in increasing the thermal conductivity of liquid-phase sintered SiC ceramics. The thermal conductivity of SiC ceramics processed from a 90% β-SiC-10% α-SiC powder mixture was 159 W/m∙K at room temperature.

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Analysis of Graphitization during Physical Vapor Transport Growth of Silicon Carbide

Materials Science Forum ◽

10.4028/www.scientific.net/msf.457-460.55 ◽

2004 ◽

Vol 457-460 ◽

pp. 55-58 ◽

Cited By ~ 8

Author(s):

Peter J. Wellmann ◽

Z.G. Herro ◽

Sakwe Aloysius Sakwe ◽

Pierre M. Masri ◽

M.V. Bogdanov ◽

...

Keyword(s):

Silicon Carbide ◽

Vapor Transport ◽

Physical Vapor Transport

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Modified Physical Vapor Transport Growth of SiC - Control of Gas Phase Composition for Improved Process Conditions

Materials Science Forum ◽

10.4028/www.scientific.net/msf.483-485.25 ◽

2005 ◽

Vol 483-485 ◽

pp. 25-30 ◽

Cited By ~ 8

Author(s):

Peter J. Wellmann ◽

Thomas L. Straubinger ◽

Patrick Desperrier ◽

Ralf Müller ◽

Ulrike Künecke ◽

...

Keyword(s):

Temperature Field ◽

Phase Composition ◽

Gas Phase ◽

Growth Conditions ◽

Vapor Transport ◽

Physical Vapor Transport ◽

Process Conditions ◽

Growth Technique ◽

Experimental Implementation ◽

P Type

We review the development of a modified physical vapor transport (M-PVT) growth technique for the preparation of SiC single crystals which makes use of an additional gas pipe into the growth cell. While the gas phase composition is basically fixed in conventional physical vapor transport (PVT) growth by crucible design and temperature field, the gas inlet of the MPVT configuration allows the direct tuning of the gas phase composition for improved growth conditions. The phrase "additional" means that only small amounts of extra gases are supplied in order to fine-tune the gas phase composition. We discuss the experimental implementation of the extra gas pipe and present numerical simulations of temperature field and mass transport in the new growth configuration. The potential of the growth technique will be outlined by showing the improvements achieved for p-type doping of 4H-SiC with aluminum, i.e. [Al]=9⋅1019cm-3 and ρ<0.2Ωcm, and n-type doping of SiC with phosphorous, i.e. [P]=7.8⋅1017cm-3.

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Thermal Diffusivity and Conductivity of La0.7Ca0.3-xSrxMnO3 (x=0 to 0.10)

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.501.319 ◽

2012 ◽

Vol 501 ◽

pp. 319-323

Author(s):

Hasan A. Alwi ◽

Lay S. Ewe ◽

Zahari Ibrahim ◽

Noor B. Ibrahim ◽

Roslan Abd-Shukor

Keyword(s):

Thermal Conductivity ◽

Electrical Conductivity ◽

Grain Size ◽

Transition Temperature ◽

Thermal Diffusivity ◽

Electrical Properties ◽

Room Temperature ◽

Electronic Contribution ◽

Insulator Metal Transition ◽

Thermal And Electrical Properties

We report the room temperature thermal conductivity κ and thermal diffusivity α of polycrystalline La0.7Ca0.3-xSrxMnO3 for x = 0 to 0.1. The samples were prepared by heating at 1220 and 1320oC. The insulator-metal transition temperature, TIM and thermal diffusivity increased with Sr content. Phonon was the dominant contributor to thermal conductivity and the electronic contribution was less than 1%. Enhancement of electrical conductivity σ and thermal diffusivity for x ≥ 0.08 was observed in both series of samples. The grain size of the samples (28 to 46 µm) does not show any affect on the thermal and electrical properties.

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Enlargement of Silicon Carbide Lely Platelet by Physical Vapor Transport Technique

Materials and Manufacturing Processes ◽

10.1080/10426914.2013.840911 ◽

2013 ◽

Vol 28 (11) ◽

pp. 1248-1252 ◽

Cited By ~ 2

Author(s):

Yonggui Shi ◽

Xinghua Yang ◽

Dong Wang ◽

Peng Zhang ◽

Jincheng Zhang ◽

...

Keyword(s):

Silicon Carbide ◽

Vapor Transport ◽

Physical Vapor Transport ◽

Transport Technique

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Growth of Silicon Carbide Nanowires by a Microwave Heating-Assisted Physical Vapor Transport Process Using Group VIII Metal Catalysts

Chemistry of Materials ◽

10.1021/cm071213r ◽

2007 ◽

Vol 19 (23) ◽

pp. 5531-5537 ◽

Cited By ~ 62

Author(s):

Siddarth G. Sundaresan ◽

Albert V. Davydov ◽

Mark D. Vaudin ◽

Igor Levin ◽

James E. Maslar ◽

...

Keyword(s):

Silicon Carbide ◽

Microwave Heating ◽

Transport Process ◽

Metal Catalysts ◽

Vapor Transport ◽

Physical Vapor Transport ◽

Group Viii ◽

Group Viii Metal

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Effects of Grain Size of Source Material on Growing 6H-SiC Bulk Crystal by Physical Vapor Transport

Materials and Manufacturing Processes ◽

10.1080/10426914.2010.544829 ◽

2012 ◽

Vol 27 (1) ◽

pp. 84-87 ◽

Cited By ~ 2

Author(s):

Yonggui Shi ◽

Peiyun Dai ◽

Jianfeng Yang ◽

Zhihao Jin ◽

Jikuan Cheng ◽

...

Keyword(s):

Grain Size ◽

Source Material ◽

Bulk Crystal ◽

Vapor Transport ◽

Physical Vapor Transport

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Studies of the Distribution of Elementary Threading Screw Dislocations in 4H Silicon Carbide Wafer

Materials Science Forum ◽

10.4028/www.scientific.net/msf.600-603.301 ◽

2008 ◽

Vol 600-603 ◽

pp. 301-304 ◽

Cited By ~ 8

Author(s):

Yi Chen ◽

Ning Zhang ◽

Xian Rong Huang ◽

David R. Black ◽

Michael Dudley

Keyword(s):

Silicon Carbide ◽

Grazing Incidence ◽

Vapor Transport ◽

Physical Vapor Transport ◽

Screw Dislocations ◽

X Ray ◽

Pyramidal Plane

The density and sense distribution of elementary threading screw dislocations in a physical vapor transport grown 3-inch 4H silicon carbide wafer have been studied. The density of TSDs ranges between 1.6×103/cm2 and 7.1×103/cm2 and the lowest density is observed at positions approximately half radius off the wafer center. The dislocation sense of elementary threading screw dislocations can be readily revealed by the asymmetric contrast of their images in grazing-incidence x-ray topographs using pyramidal plane reflections. The circumferential and radial distributions of the sense of elementary threading screw dislocations have been studied and no clear trends are observed in either distribution.

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