Large-scale synthesis of single- and multiwalled carbon nanotubes by microwave CVD

2002 ◽  
Author(s):  
Vijay K. Varadan ◽  
Jining Xie
Author(s):  
Ibrahim Awad ◽  
Leila Ladani

Due to their superior mechanical and electrical properties, multiwalled carbon nanotubes (MWCNTs) have the potential to be used in many nano-/micro-electronic applications, e.g., through silicon vias (TSVs), interconnects, transistors, etc. In particular, use of MWCNT bundles inside annular cylinders of copper (Cu) as TSV is proposed in this study. However, the significant difference in scale makes it difficult to evaluate the interfacial mechanical integrity. Cohesive zone models (CZM) are typically used at large scale to determine the mechanical adherence at the interface. However, at molecular level, no routine technique is available. Molecular dynamic (MD) simulations is used to determine the stresses that are required to separate MWCNTs from a copper slab and generate normal stress–displacement curves for CZM. Only van der Waals (vdW) interaction is considered for MWCNT/Cu interface. A displacement controlled loading was applied in a direction perpendicular to MWCNT's axis in different cases with different number of walls and at different temperatures and CZM is obtained for each case. Furthermore, their effect on the CZM key parameters (normal cohesive strength (σmax) and the corresponding displacement (δn) has been studied. By increasing the number of the walls of the MWCNT, σmax was found to nonlinearly decrease. Displacement at maximum stress, δn, showed a nonlinear decrease as well with increasing the number of walls. Temperature effect on the stress–displacement curves was studied. When temperature was increased beyond 1 K, no relationship was found between the maximum normal stress and temperature. Likewise, the displacement at maximum load did not show any dependency to temperature.


2010 ◽  
Vol 109 (1) ◽  
pp. 25-30 ◽  
Author(s):  
S A Manafi ◽  
M H Amin ◽  
M R Rahimipour ◽  
E Salahi ◽  
A Kazemzadeh

2011 ◽  
Vol 56 (27) ◽  
pp. 10069-10076 ◽  
Author(s):  
Junhua Yuan ◽  
Xiaoli Jin ◽  
Na Li ◽  
Jianrong Chen ◽  
Jigen Miao ◽  
...  

2003 ◽  
Vol 02 (01n02) ◽  
pp. 1-6 ◽  
Author(s):  
Liu Zhi ◽  
Huai H. Song

We report a novel method to synthesize multiwalled carbon nanotubes (MWNTs) in large scale at 470°C. TEM and Roman spectra analysis show that dominating graphite crystalline coexists with amorphous carbon in MWNTs. XRD and TGA results suggest that fcc cobalt plays a catalytic role in the growth process of MWNTs, which exists and stable inside the carbon layers of MWNTs. The synthesis method is simple and can easily ensure adequate stability and reproducibility. Therefore the method is possibly suited to industrialized synthesizing process of MWNTs due to these advantages.


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