An: Ab initio study of the nickel-catalyzed transformation of amorphous carbon into graphene in rapid thermal processing

Shuang Chen, Wei Xiong, Yun Shen Zhou, Yong Feng Lu, Xiao Cheng Zeng

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

Ab initio molecular dynamics (AIMD) simulations are employed to investigate the chemical mechanism underlying the Ni-catalyzed transformation of amorphous carbon (a-C) into graphene in the rapid thermal processing (RTP) experiment to directly grow graphene on various dielectric surfaces via the evaporation of surplus Ni and C at 1100 °C (below the melting point of bulk Ni). It is found that the a-C-to-graphene transformation entails the metal-induced crystallization and layer exchange mechanism, rather than the conventional dissolution/precipitation mechanism typically involved in Ni-catalyzed chemical vapor deposition (CVD) growth of graphene. The multi-layer graphene can be tuned by changing the relative thicknesses of deposited a-C and Ni thin films. Our AIMD simulations suggest that the easy evaporation of surplus Ni with excess C is likely attributed to the formation of a viscous-liquid-like Ni-C solution within the temperature range of 900-1800 K and to the faster diffusion of C atoms than that of Ni atoms above 600 K. Even at room temperature, sp3-C atoms in a-C are quickly converted to sp2-C atoms in the course of the simulation, and the graphitic C formation can occur at low temperature. When the temperature is as high as 1200 K, the grown graphitic structures reversely dissolve into Ni. Because the rate of temperature increase is considerably faster in the AIMD simulations than in realistic experiments, defects in the grown graphitic structures are kinetically trapped. In this kinetic growth stage, the carbon structures grown from sp3-carbon or from sp2-carbon exhibit marked differences.

Original languageEnglish (US)
Pages (from-to)9746-9755
Number of pages10
JournalNanoscale
Volume8
Issue number18
DOIs
StatePublished - May 14 2016

Fingerprint

Rapid thermal processing
Graphite
Amorphous carbon
Nickel
Graphene
Molecular dynamics
Atoms
Carbon
Computer simulation
Evaporation
Temperature
Growth kinetics
Crystallization
Melting point
Chemical vapor deposition
Dissolution
Metals
Experiments
Thin films
Defects

ASJC Scopus subject areas

  • Materials Science(all)

Cite this

An : Ab initio study of the nickel-catalyzed transformation of amorphous carbon into graphene in rapid thermal processing. / Chen, Shuang; Xiong, Wei; Zhou, Yun Shen; Lu, Yong Feng; Zeng, Xiao Cheng.

In: Nanoscale, Vol. 8, No. 18, 14.05.2016, p. 9746-9755.

Research output: Contribution to journalArticle

@article{81bc5476ae9d4cf797cdf6429e7c409d,
title = "An: Ab initio study of the nickel-catalyzed transformation of amorphous carbon into graphene in rapid thermal processing",
abstract = "Ab initio molecular dynamics (AIMD) simulations are employed to investigate the chemical mechanism underlying the Ni-catalyzed transformation of amorphous carbon (a-C) into graphene in the rapid thermal processing (RTP) experiment to directly grow graphene on various dielectric surfaces via the evaporation of surplus Ni and C at 1100 °C (below the melting point of bulk Ni). It is found that the a-C-to-graphene transformation entails the metal-induced crystallization and layer exchange mechanism, rather than the conventional dissolution/precipitation mechanism typically involved in Ni-catalyzed chemical vapor deposition (CVD) growth of graphene. The multi-layer graphene can be tuned by changing the relative thicknesses of deposited a-C and Ni thin films. Our AIMD simulations suggest that the easy evaporation of surplus Ni with excess C is likely attributed to the formation of a viscous-liquid-like Ni-C solution within the temperature range of 900-1800 K and to the faster diffusion of C atoms than that of Ni atoms above 600 K. Even at room temperature, sp3-C atoms in a-C are quickly converted to sp2-C atoms in the course of the simulation, and the graphitic C formation can occur at low temperature. When the temperature is as high as 1200 K, the grown graphitic structures reversely dissolve into Ni. Because the rate of temperature increase is considerably faster in the AIMD simulations than in realistic experiments, defects in the grown graphitic structures are kinetically trapped. In this kinetic growth stage, the carbon structures grown from sp3-carbon or from sp2-carbon exhibit marked differences.",
author = "Shuang Chen and Wei Xiong and Zhou, {Yun Shen} and Lu, {Yong Feng} and Zeng, {Xiao Cheng}",
year = "2016",
month = "5",
day = "14",
doi = "10.1039/c5nr08614k",
language = "English (US)",
volume = "8",
pages = "9746--9755",
journal = "Nanoscale",
issn = "2040-3364",
publisher = "Royal Society of Chemistry",
number = "18",

}

TY - JOUR

T1 - An

T2 - Ab initio study of the nickel-catalyzed transformation of amorphous carbon into graphene in rapid thermal processing

AU - Chen, Shuang

AU - Xiong, Wei

AU - Zhou, Yun Shen

AU - Lu, Yong Feng

AU - Zeng, Xiao Cheng

PY - 2016/5/14

Y1 - 2016/5/14

N2 - Ab initio molecular dynamics (AIMD) simulations are employed to investigate the chemical mechanism underlying the Ni-catalyzed transformation of amorphous carbon (a-C) into graphene in the rapid thermal processing (RTP) experiment to directly grow graphene on various dielectric surfaces via the evaporation of surplus Ni and C at 1100 °C (below the melting point of bulk Ni). It is found that the a-C-to-graphene transformation entails the metal-induced crystallization and layer exchange mechanism, rather than the conventional dissolution/precipitation mechanism typically involved in Ni-catalyzed chemical vapor deposition (CVD) growth of graphene. The multi-layer graphene can be tuned by changing the relative thicknesses of deposited a-C and Ni thin films. Our AIMD simulations suggest that the easy evaporation of surplus Ni with excess C is likely attributed to the formation of a viscous-liquid-like Ni-C solution within the temperature range of 900-1800 K and to the faster diffusion of C atoms than that of Ni atoms above 600 K. Even at room temperature, sp3-C atoms in a-C are quickly converted to sp2-C atoms in the course of the simulation, and the graphitic C formation can occur at low temperature. When the temperature is as high as 1200 K, the grown graphitic structures reversely dissolve into Ni. Because the rate of temperature increase is considerably faster in the AIMD simulations than in realistic experiments, defects in the grown graphitic structures are kinetically trapped. In this kinetic growth stage, the carbon structures grown from sp3-carbon or from sp2-carbon exhibit marked differences.

AB - Ab initio molecular dynamics (AIMD) simulations are employed to investigate the chemical mechanism underlying the Ni-catalyzed transformation of amorphous carbon (a-C) into graphene in the rapid thermal processing (RTP) experiment to directly grow graphene on various dielectric surfaces via the evaporation of surplus Ni and C at 1100 °C (below the melting point of bulk Ni). It is found that the a-C-to-graphene transformation entails the metal-induced crystallization and layer exchange mechanism, rather than the conventional dissolution/precipitation mechanism typically involved in Ni-catalyzed chemical vapor deposition (CVD) growth of graphene. The multi-layer graphene can be tuned by changing the relative thicknesses of deposited a-C and Ni thin films. Our AIMD simulations suggest that the easy evaporation of surplus Ni with excess C is likely attributed to the formation of a viscous-liquid-like Ni-C solution within the temperature range of 900-1800 K and to the faster diffusion of C atoms than that of Ni atoms above 600 K. Even at room temperature, sp3-C atoms in a-C are quickly converted to sp2-C atoms in the course of the simulation, and the graphitic C formation can occur at low temperature. When the temperature is as high as 1200 K, the grown graphitic structures reversely dissolve into Ni. Because the rate of temperature increase is considerably faster in the AIMD simulations than in realistic experiments, defects in the grown graphitic structures are kinetically trapped. In this kinetic growth stage, the carbon structures grown from sp3-carbon or from sp2-carbon exhibit marked differences.

UR - http://www.scopus.com/inward/record.url?scp=84971634704&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84971634704&partnerID=8YFLogxK

U2 - 10.1039/c5nr08614k

DO - 10.1039/c5nr08614k

M3 - Article

C2 - 27117235

AN - SCOPUS:84971634704

VL - 8

SP - 9746

EP - 9755

JO - Nanoscale

JF - Nanoscale

SN - 2040-3364

IS - 18

ER -