Thermal conductivity of silicon carbide densified with rare-earth oxide additives

SiC ceramics were prepared from a β–SiC powder doped with two different sintering additives—a mixture of La2O3and Y2O3and a mixture of Al2O3and Y2O3—by hot pressing and annealing. Their microstructures, phase compositions, lattice oxygen contents, and thermal conductivities were evaluated. The SiC doped with rare-earth oxides attained thermal conductivities in excess of 200 W/(m K); however, the SiC doped with additives containing alumina had thermal conductivities lower than 71 W/(m K). The high thermal conductivity of the rare-earth-oxide-doped SiC was attributed to the low oxygen content in SiC lattice, high SiC–SiC contiguity, and lack of β– to α–SiC polytypic transformation. The low thermal conductivity of the alumina-doped SiC was attributed to the point defects resulting from the dissolution of Al2O3into SiC lattice and the occurrence of polytypic transformation.

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Role of rare earth oxide particles on the oxidation behaviour of silicon carbide coated 2.5D carbon fibre preforms

Open Ceramics ◽

10.1016/j.oceram.2020.100018 ◽

2020 ◽

Vol 2 ◽

pp. 100018

Author(s):

T.S.R.C. Murthy ◽

Lucas Reeman ◽

Ji Zou ◽

Vinothini Venkatachalam ◽

Ben Baker ◽

...

Keyword(s):

Silicon Carbide ◽

Rare Earth ◽

Carbon Fibre ◽

Rare Earth Oxide ◽

Oxidation Behaviour ◽

Oxide Particles

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Characterization of crystalline rare-earth oxide high-K dielectrics grown by molecular beam epitaxy on silicon carbide

Journal of Vacuum Science & Technology B Microelectronics and Nanometer Structures Processing Measurement and Phenomena ◽

10.1116/1.2214702 ◽

2006 ◽

Vol 24 (4) ◽

pp. 2115 ◽

Cited By ~ 25

Author(s):

A. Fissel ◽

M. Czernohorsky ◽

H. J. Osten

Keyword(s):

Silicon Carbide ◽

Rare Earth ◽

Molecular Beam Epitaxy ◽

Molecular Beam ◽

Rare Earth Oxide ◽

High K

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Fabrication and Microstructure of Electrically Conductive AlN with High Thermal Conductivity

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.484.57 ◽

2011 ◽

Vol 484 ◽

pp. 57-60

Author(s):

Takafumi Kusunose ◽

Tohru Sekino ◽

Koiichi Niihara

Keyword(s):

Thermal Conductivity ◽

Electrical Conductivity ◽

Rare Earth ◽

Sintering Temperature ◽

Rare Earth Oxide ◽

High Thermal Conductivity ◽

Boundary Phase ◽

Sudden Increase ◽

Electrically Conductive ◽

Electrical Conductivities

The electrically conductive AlN with high thermal conductivity were successfully fabricated by sintering AlN with a composite additive of 1wt.% Y2O3 and 4wt.% CeO2 in carbon-reduced atmosphere at over 1600 °C. The sudden increase in electrical conductivity is thought to be caused by transition of grain boundary phase from rare-earth oxide to rare-earth oxycarbide. Their electrical conductivities and thermal conductivities increased with increasing sintering temperature. Additionally, sintering temperature influenced the resultant microstructures.

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