TY - JOUR
T1 - Amorphized graphene
T2 - A stiff material with low thermal conductivity
AU - Mortazavi, Bohayra
AU - Fan, Zheyong
AU - Pereira, Luiz Felipe C.
AU - Harju, Ari
AU - Rabczuk, Timon
N1 - Funding Information:
BM and TR greatly acknowledge the financial support by European Research Council for COMBAT project (Grant number 615132 ). ZF and AH are supported by the Academy of Finland through its Centres of Excellence Program (project no. 251748 ) and they acknowledge the computational resources provided by Aalto Science-IT project and Finland's IT Center for Science (CSC). LFCP acknowledges financial support from Brazilian government agency CAPES via its Science Without Borders program.
Publisher Copyright:
© 2016 Elsevier Ltd. All rights reserved.
PY - 2016/7
Y1 - 2016/7
N2 - All-carbon heterostructures have been produced recently via focused ion beam patterning of single layer graphene. Amorphized graphene is similar to a graphene sheet in which some hexagons are replaced by a combination of pentagonal, heptagonal and octagonal rings. The present investigation provides a general view regarding phonon and load transfer along amorphous graphene. The developed models for the evaluation of mechanical and thermal conductivity properties yield accurate results for pristine graphene and acquired findings for amorphized graphene films are size independent. Our atomistic results show that amorphous graphene sheets could exhibit a remarkably high elastic modulus of ∼500 GPa and tensile strengths of ∼50 GPa at room temperature. However, our results show that mechanical properties of amorphous graphene decline at higher temperatures. Furthermore, we show that amorphized graphene present a low thermal conductivity ∼15 W/mK which is two orders of magnitude smaller than pristine graphene, and we verify that its thermal conductivity is almost insensitive to temperature since it is dominated by phonon-defect scattering rather than phonon-phonon scattering. Finally, our results show that amorphized graphene structures present a remarkably high elastic modulus and mechanical strength, along with a low thermal conductivity, which is an unusual combination for carbon-based materials.
AB - All-carbon heterostructures have been produced recently via focused ion beam patterning of single layer graphene. Amorphized graphene is similar to a graphene sheet in which some hexagons are replaced by a combination of pentagonal, heptagonal and octagonal rings. The present investigation provides a general view regarding phonon and load transfer along amorphous graphene. The developed models for the evaluation of mechanical and thermal conductivity properties yield accurate results for pristine graphene and acquired findings for amorphized graphene films are size independent. Our atomistic results show that amorphous graphene sheets could exhibit a remarkably high elastic modulus of ∼500 GPa and tensile strengths of ∼50 GPa at room temperature. However, our results show that mechanical properties of amorphous graphene decline at higher temperatures. Furthermore, we show that amorphized graphene present a low thermal conductivity ∼15 W/mK which is two orders of magnitude smaller than pristine graphene, and we verify that its thermal conductivity is almost insensitive to temperature since it is dominated by phonon-defect scattering rather than phonon-phonon scattering. Finally, our results show that amorphized graphene structures present a remarkably high elastic modulus and mechanical strength, along with a low thermal conductivity, which is an unusual combination for carbon-based materials.
UR - http://www.scopus.com/inward/record.url?scp=84961677942&partnerID=8YFLogxK
U2 - 10.1016/j.carbon.2016.03.007
DO - 10.1016/j.carbon.2016.03.007
M3 - Article
AN - SCOPUS:84961677942
SN - 0008-6223
VL - 103
SP - 318
EP - 326
JO - Carbon
JF - Carbon
ER -