Due to their unique properties and appealing applications,low dimensional sp^(3)carbon nanostructures have attracted increasing attention recently.Based on the beam theory and atomistic studies,this work carries out a...Due to their unique properties and appealing applications,low dimensional sp^(3)carbon nanostructures have attracted increasing attention recently.Based on the beam theory and atomistic studies,this work carries out a comprehensive investigation on the vibrational properties of the ultrathin carbon nanothreads(NTH).Size effect is observed in transverse free vibrations of NTHs.To quantify such effects,the modified couple stress theory(MCST)is utilized to modify the Timoshenko beam theory.According to the first four order frequencies of NTHs from atomistic simulations,the critical length scale parameter of MCST is calibrated as 0.1 nm.It is shown that MCST has minor effect on the first four order modal shapes,except for the clamped boundary.MCST makes the modal shapes at the clamped boundary closer to those observed in atomistic simulations.This study suggests that to some extent the MCST-based Timoshenko beam theory can well describe the transverse vibration characteristics of the ultrafine NTHs,which are helpful for designing and fabricating the NTH-based nanoscale mechanical resonators.展开更多
The diamond nanothread(DNT), a new one-dimensional(1 D) full carbon sp3 structure that has been successfully synthesized recently, has attracted widespread attention in the carbon community. By using the first-princip...The diamond nanothread(DNT), a new one-dimensional(1 D) full carbon sp3 structure that has been successfully synthesized recently, has attracted widespread attention in the carbon community. By using the first-principles calculation method of density functional theory(DFT), we have studied the effects of 3 d transition metal(TM) atomic doping on the electronic and magnetic properties of DNT. The results show that the spin-polarized semiconductor characteristics are achieved by doping Sc, V, Cr, Mn, and Co atoms in the DNT system. The magnetic moment ranges from 1.00 μB to 3.00 μB and the band gap value is from 0.35 e V to 2.54 e V. The Fe-doped DNT system exhibits spin-metallic state with a magnetic moment of 2.58 μB, while the Ti and Ni-doped DNT systems are nonmagnetic semiconductors. These results indicate that the 3 d TM atoms doping can modulate the electronic and magnetic properties of 1 D-DNT effectively, and the TM-doped DNT systems have potential applications in the fields of electronics, optoelectronics, and spintronics.展开更多
Low dimensional sp~3 carbon nanostructures have attracted increasing attention recently, due to their unique properties and appealing applications. Based on in silico studies, this work exploits the impacts from funct...Low dimensional sp~3 carbon nanostructures have attracted increasing attention recently, due to their unique properties and appealing applications. Based on in silico studies, this work exploits the impacts from functional groups on the tensile properties of carbon nanothreads(NTH)– a new sp~3 carbon nanostructure. It is found that functional groups will alter the local bond configuration and induce initial stress concentration, which significantly reduces the fracture strain/strength of NTH. Different functional types lead to different local bond reconfigurations, and introduce different impacts on NTH. Further studies reveal that the tensile properties decreases generally when the content of functional groups increases. However, some NTHs with higher content of functional groups exhibit higher fracture strain/strength than their counterparts with lower percentage. Such observations are attributed to the synergetic effects from the sample length, self-oscillation, and distribution of functional groups. Simulations show that the tensile behaviour of NTH with the same functional percentage differs when the distribution pattern varies. Overall, ethyl groups are found to induce larger degradation on the tensile properties of NTH than methyl and phenyl groups. This study provides a comprehensive understanding of the influence from functional groups, which should be beneficial to the engineering applications of NTH.展开更多
This review summarizes the current studies of the thermal transport properties of one-dimensional(1D)carbon nano-materials and nanoarchitectures.Considering different hybridization states of carbon,emphases are laid o...This review summarizes the current studies of the thermal transport properties of one-dimensional(1D)carbon nano-materials and nanoarchitectures.Considering different hybridization states of carbon,emphases are laid on a variety of 1D carbon nanomaterials,such as diamond nanothreads,penta-graphene nanotubes,supernanotnbes,and carbyne.Based on experimental measurements and simulation/calculation results,we discuss the dependence of the thermal conductivity of these 1D carbon nanomaterials on a wide range of factors,including the size effect,temperature influence,strain effect,and others.This review provides an overall understanding of the thermal transport properties of 1D carbon nanomaterials and nanoarchitectures,which paves the way for effective thermal management at nanoscale.展开更多
基金the National Natural Science Foundation of China(Grant No.12102176)the China Postdoctoral Science Foundation(Grant No.2022M711617)+1 种基金the Natural Science Foundation of Jiangsu Province of China(Grant No.BK20210274)Partially supported by the High Performance Computing Platform of Nanjing University of Aeronautics and Astronautics。
文摘Due to their unique properties and appealing applications,low dimensional sp^(3)carbon nanostructures have attracted increasing attention recently.Based on the beam theory and atomistic studies,this work carries out a comprehensive investigation on the vibrational properties of the ultrathin carbon nanothreads(NTH).Size effect is observed in transverse free vibrations of NTHs.To quantify such effects,the modified couple stress theory(MCST)is utilized to modify the Timoshenko beam theory.According to the first four order frequencies of NTHs from atomistic simulations,the critical length scale parameter of MCST is calibrated as 0.1 nm.It is shown that MCST has minor effect on the first four order modal shapes,except for the clamped boundary.MCST makes the modal shapes at the clamped boundary closer to those observed in atomistic simulations.This study suggests that to some extent the MCST-based Timoshenko beam theory can well describe the transverse vibration characteristics of the ultrafine NTHs,which are helpful for designing and fabricating the NTH-based nanoscale mechanical resonators.
基金National Natural Science Foundation of China(Grant Nos.21673296 and 11664038)the Natural Science Foundation of Xinjiang Uygur Autonomous Region of China(Grant No.2019D01C038).
文摘The diamond nanothread(DNT), a new one-dimensional(1 D) full carbon sp3 structure that has been successfully synthesized recently, has attracted widespread attention in the carbon community. By using the first-principles calculation method of density functional theory(DFT), we have studied the effects of 3 d transition metal(TM) atomic doping on the electronic and magnetic properties of DNT. The results show that the spin-polarized semiconductor characteristics are achieved by doping Sc, V, Cr, Mn, and Co atoms in the DNT system. The magnetic moment ranges from 1.00 μB to 3.00 μB and the band gap value is from 0.35 e V to 2.54 e V. The Fe-doped DNT system exhibits spin-metallic state with a magnetic moment of 2.58 μB, while the Ti and Ni-doped DNT systems are nonmagnetic semiconductors. These results indicate that the 3 d TM atoms doping can modulate the electronic and magnetic properties of 1 D-DNT effectively, and the TM-doped DNT systems have potential applications in the fields of electronics, optoelectronics, and spintronics.
基金Support from the ARC Discovery Project (DP180103009, DP200102546)the High-Performance Computing (HPC) resources provided by the Queensland University of Technology(QUT)。
文摘Low dimensional sp~3 carbon nanostructures have attracted increasing attention recently, due to their unique properties and appealing applications. Based on in silico studies, this work exploits the impacts from functional groups on the tensile properties of carbon nanothreads(NTH)– a new sp~3 carbon nanostructure. It is found that functional groups will alter the local bond configuration and induce initial stress concentration, which significantly reduces the fracture strain/strength of NTH. Different functional types lead to different local bond reconfigurations, and introduce different impacts on NTH. Further studies reveal that the tensile properties decreases generally when the content of functional groups increases. However, some NTHs with higher content of functional groups exhibit higher fracture strain/strength than their counterparts with lower percentage. Such observations are attributed to the synergetic effects from the sample length, self-oscillation, and distribution of functional groups. Simulations show that the tensile behaviour of NTH with the same functional percentage differs when the distribution pattern varies. Overall, ethyl groups are found to induce larger degradation on the tensile properties of NTH than methyl and phenyl groups. This study provides a comprehensive understanding of the influence from functional groups, which should be beneficial to the engineering applications of NTH.
基金Project supported by Australian Research Council(ARC)Discovery Project DP170102861
文摘This review summarizes the current studies of the thermal transport properties of one-dimensional(1D)carbon nano-materials and nanoarchitectures.Considering different hybridization states of carbon,emphases are laid on a variety of 1D carbon nanomaterials,such as diamond nanothreads,penta-graphene nanotubes,supernanotnbes,and carbyne.Based on experimental measurements and simulation/calculation results,we discuss the dependence of the thermal conductivity of these 1D carbon nanomaterials on a wide range of factors,including the size effect,temperature influence,strain effect,and others.This review provides an overall understanding of the thermal transport properties of 1D carbon nanomaterials and nanoarchitectures,which paves the way for effective thermal management at nanoscale.
