Aspect ratio evaluation of carbon nanotubes grown on calcium carbonate substrate for different temperatures and precursor flow times

作者：Patil K N^*; Solanki C S

来源：Journal of Nano Research, 2008, 4: 127-133.

• Carbon nanotubes
• aspect ratio
• Transmission electron microscope

Carbon Nanotubes (CNTs) are excellent material with a variety of physical, electrical, and mechanical properties. The average aspect ratio is evaluated for samples synthesized at,different temperature and time of precursor flow. The experiments were conducted on calcium carbonate (CaCO(3)) substrate with iron-cobalt (Fe-Co) as a catalyst. Acetylene (C(2)H(2)) was used as a precursor gas and argon (Ar) as a carrier gas. The experiments were performed at temperatures ranging from 600 degrees C to 900 degrees C in step of 100 degrees C with time of precursor flow varying from 15 minutes to 75 minutes in the step of 15 minutes. The partial pressure of C(2)H(2) and At kept constant during synthesis of CNT. The mass flow rate Of C(2)H(2) and Ar were 2 liters/hour and 60 liters/hour respectively during synthesis of CNT. The characterization of CNT was done with SEM, EDX, and TEM microscopes. Average aspect ratio of CNT is estimated using image analysis software. Most of nanotubes grown present an average diameter of 40 nm. The minimum and maximum diameter found are 12.5 nm and 106 nm respectively. It is observed that average aspect ratio ranges from 25 to 58.

• 出版日期2008