| Autor: |
Hundt, Morten, Sadler, Patrick, Levchenko, Igor, Wolter, Matthias, Kersten, Holger, Ostrikov, Kostya (Ken) |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; Jun2011, Vol. 109 Issue 12, p123305, 7p, 1 Black and White Photograph, 1 Diagram, 5 Graphs |
| Abstrakt: |
Quantum cascade laser absorption spectroscopy was used to measure the absolute concentration of acetylene in situ during the nanoparticle growth in Ar + C2H2 RF plasmas. It is demonstrated that the nanoparticle growth exhibits a periodical behavior, with the growth cycle period strongly dependent on the initial acetylene concentration in the chamber. Being 300 s at 7.5% of acetylene in the gas mixture, the growth cycle period decreases with the acetylene concentration increasing; the growth eventually disappears when the acetylene concentration exceeds 32%. During the nanoparticle growth, the acetylene concentration is small and does not exceed 4.2% at radio frequency (RF) power of 4 W, and 0.5% at RF power of 20 W. An injection of a single acetylene pulse into the discharge also results in the nanoparticle nucleation and growth. The absorption spectroscopy technique was found to be very effective for the time-resolved measurement of the hydrocarbon content in nanoparticle-generating plasmas. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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