scholarly journals Experimental Microwave Complex Conductivity Extraction of Vertically Aligned MWCNT Bundles for Microwave Subwavelength Antenna Design

Micromachines ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 566 ◽  
Author(s):  
Charlotte Tripon-Canseliet ◽  
Stephane Xavier ◽  
Yifeng Fu ◽  
Jean-Paul Martinaud ◽  
Afshin Ziaei ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Silicon Substrate ◽  
Electrical Impedance ◽  
Antenna Design ◽  
Complex Conductivity ◽  
Microwave Frequencies ◽  
Multi Wall Carbon Nanotubes ◽  
Capacitive Behavior ◽  
Resonance Shift ◽  
Vertically Aligned

This paper reports the extraction of electrical impedance at microwave frequencies of vertically aligned multi-wall carbon nanotubes (VA MWCNT) bundles/forests grown on a silicon substrate. Dedicated resonating devices were designed for antenna application, operating around 10 GHz and benefiting from natural inductive/capacitive behavior or complex conductivity in the microwave domain. As obtained from S-parameters measurements, the capacitive and inductive behaviors of VA MWCNT bundles were deduced from device frequency resonance shift.

Synthesis of Vertically Aligned Carbon Nanotubes by dc PECVD

2006 ◽  
Vol 326-328 ◽  
pp. 333-336
Author(s):  
Yun Young Bang ◽  
Tae Jin Je ◽  
Kyung Hyun Whang ◽  
Won Seok Chang
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Carbon Source ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Catalyst Layer ◽  
Metal Catalyst ◽  
Synthesis Methods ◽  
Multi Wall Carbon Nanotubes ◽  
Vertically Aligned

Chemical vapor deposition (CVD) is one of the various synthesis methods that have been employed for CNT growth. In particular, Ren et al reported that large areas of vertically aligned multi-wall carbon nanotubes could be grown using plasma enhanced chemical vapor deposition (PECVD). In the present study, we synthesized aligned CNT arrays using a direct current (dc) PECVD system. The synthesis of CNTs requires a metal catalyst layer, etchant gas, and a carbon source. In this study, the substrate consisted of Si wafers with 10, 30, and 50 nm Ni-sputtered film. Ammonia (NH3) and acetylene (C2H2) were used as the etchant gases and carbon source, respectively. NH3 pretreatment was processed using a flow rate of 180 sccm for 10 min. CNTs were grown on pretreated substrates at 30% C2H2:NH3 flow ratios for 10 min. Carbon nanotubes with diameters ranging from 60 to 80 nanometers and lengths of about 2.7 μm were obtained. Vertical alignment of the carbon nanotubes was observed by FE-SEM.

Sign in / Sign up

Export Citation Format

Share Document