Highly pure pentacene crystals grown by physical vapor transport: the critical role of the carrier gas

Journal of Materials Chemistry C ◽

10.1039/d0tc04698a ◽

2021 ◽

Author(s):

Hye Soo Kim ◽

Soyoung Kim ◽

Jin Young Koo ◽

Hee Cheul Choi

Keyword(s):

Physical Properties ◽

High Purity ◽

Transport Process ◽

Critical Role ◽

Vapor Transport ◽

Physical Vapor Transport ◽

Carrier Gas ◽

Efficient Approach ◽

Carrier Gases

An efficient approach to obtaining high purity pentacene crystals via physical vapor transport process is reported, utilizing the physical properties of carrier gases.

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Critical role of anion on porous biochar structure and potassium release during potassium–assisted pyrolysis process

Green Chemistry ◽

10.1039/d1gc03072h ◽

2021 ◽

Author(s):

Mingwei Xia ◽

Wei Chen ◽

Jing Wu ◽

Yingquan Chen ◽

Haiping Yang ◽

...

Keyword(s):

Critical Role ◽

Pyrolysis Process ◽

Efficient Approach ◽

Potassium Release

Potassium-assisted pyrolysis is an efficient approach of preparing versatile porous biochar. However, among potassium additives, it is hard to decide which is more applicable due to lack of understanding of...

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Molecular-scale investigation of the oxidation behavior of chromia-forming alloys in high-temperature CO2

npj Materials Degradation ◽

10.1038/s41529-021-00194-1 ◽

2021 ◽

Vol 5 (1) ◽

Author(s):

Richard P. Oleksak ◽

Rafik Addou ◽

Bharat Gwalani ◽

John P. Baltrus ◽

Tao Liu ◽

...

Keyword(s):

High Temperature ◽

Power Systems ◽

High Purity ◽

Photoelectron Spectroscopy ◽

Ambient Pressure ◽

Critical Role ◽

Atomic Scale ◽

Atomic Diffusion ◽

Carbon Transport

AbstractCurrent and future power systems require chromia-forming alloys compatible with high-temperature CO2. Important questions concerning the mechanisms of oxidation and carburization remain unanswered. Herein we shed light onto these processes by studying the very initial stages of oxidation of Fe22Cr and Fe22Ni22Cr model alloys. Ambient-pressure X-ray photoelectron spectroscopy enabled in situ analysis of the oxidizing surface under 1 mbar of flowing CO2 at temperatures up to 530 °C, while postexposure analyses revealed the structure and composition of the oxidized surface at the near-atomic scale. We found that gas purity played a critical role in the kinetics of the reaction, where high purity CO2 promoted the deposition of carbon and the selective oxidation of Cr. In contrast, no carbon deposition occurred in low purity CO2 and Fe oxidation ensued, thus highlighting the critical role of impurities in defining the early oxidation pathway of the alloy. The Cr-rich oxide formed on Fe22Cr in high purity CO2 was both thicker and more permeable to carbon compared to that formed on Fe22Ni22Cr, where carbon transport appeared to occur by atomic diffusion through the oxide. Alternatively, the Fe-rich oxide formed in low purity CO2 suggested carbon transport by molecular CO2.

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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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Influence of crucible shape on mass transport in AlN crystal growth by physical vapor transport process

Journal of Crystal Growth ◽

10.1016/j.jcrysgro.2019.02.059 ◽

2019 ◽

Vol 515 ◽

pp. 21-25 ◽

Cited By ~ 2

Author(s):

Qikun Wang ◽

Jiali Huang ◽

Danyang Fu ◽

Guangdong He ◽

Dan Lei ◽

...

Keyword(s):

Crystal Growth ◽

Mass Transport ◽

Transport Process ◽

Vapor Transport ◽

Physical Vapor Transport

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Generation of radical species in CVD grown pristine and N-doped solid carbon spheres using H2 and Ar as carrier gases

RSC Advances ◽

10.1039/c7ra03142d ◽

2017 ◽

Vol 7 (34) ◽

pp. 21187-21195 ◽

Cited By ~ 12

Author(s):

Bridget K. Mutuma ◽

Boitumelo J. Matsoso ◽

Kamalakannan Ranganathan ◽

Jonathan M. Keartland ◽

Daniel Wamwangi ◽

...

Keyword(s):

Solid Carbon ◽

Carbon Spheres ◽

Radical Species ◽

Carrier Gas ◽

Carrier Gases

A mechanism showing the role of carrier gas on the N-configuration of the post-N-doped CSs synthesized in the presence of (a) H2 and (b) Ar, respectively.

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