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Optical spectroscopy and langmuir probe diagnostics of microwave plasma in synthesis of graphene-based nanomaterials
| Content Provider | Semantic Scholar |
|---|---|
| Author | Tuesta, Alfredo D. |
| Copyright Year | 2014 |
| Abstract | Tuesta, Alfredo D. Ph.D., Purdue University, December 2014. Optical Spectroscopy and Langmuir Probe Diagnostics of Microwave Plasma in Synthesis of Graphenebased Nanomaterials. Major Professors: Timothy S. Fisher and Robert P. Lucht, School of Mechanical Engineering. Along with the revolutionary discovery and development of carbon nanostructures, such as carbon nanotubes and graphitic sheets, has arrived the potential for their application in the fields of medicine, bioscience and engineering due to their exceptional structural, thermal and electrical properties. As roll-to-roll plasma deposition systems begin to provide means for large scale production of these nanodevices, a detailed understanding of the environment responsible for their synthesis is imperative in order to more accurately design and control the growth of carbon nanodevices. To date, the understanding of the chemistry and kinetics that govern the synthesis of carbon nanodevices is only partially understood. In response to this need, the plasma environment of a microwave plasma chemical vapor deposition reactor has been studied. Coherent anti-Stokes Raman scattering spectroscopy was used to probe the H2 molecules in the plasma under various parametric conditions. The rotational temperature of H2 was found to increase with reactor pressure, plasma generator power, and distance from the deposition surface. At 10 Torr, the temperature range is approximately 700 to 1200 K while at 30 Torr it is 1200 to 2000 K. Also, the introduction of CH4 and N2 to the plasma increases the rotational temperature consistently. However, the number density of H2 in the plasma does not significantly deviate from theoretical values corresponding to conditions without the plasma indicating that the microwave plasma is weakly ionized and that the rotational temperatures obtained approximate the translation temperature of H2. The spectral region of the vibrational |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=1540&context=open_access_dissertations |
| Alternate Webpage(s) | http://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=1540&context=open_access_dissertations |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
