Interaction of ambient nitrogen gas and laser ablated carbon plume: Formation of CN

Abstract

Pulsed laser ablated carbon plasma in a nitrogen background gas in the pressure range from 10 mTorr to 100 Torr is investigated by optical emission spectroscopy using 1.064 and 0.355 lm laser wavelengths. C 2 and CN emission bands dominated the emitted spectrum at all ambient gas pressures at low incident laser intensity commonly used for pulsed laser deposition of thin films. The light intensity of C 2 and CN band heads is highly dependent on laser wavelength, laser energy, and ambient gas pressures. Emission from N þ 2 was detected at all nitrogen pressures. N I and N II are also observed in the emitted spectrum at the background gas pressure greater than 1 Torr. The vibrational temperature of CN species is found to be greater than that of C 2 species. The mechanism of formation of C 2 and CN molecules is discussed. Ó

Evolution of Laser Plume upon Graphite Ablation in Vacuum and Nitrogen

“…The sequence ∆υ = +2 for the Swan system of the ë 2 molecule is more distinct, intense bands of the CN molecule (sequence ∆υ = 0, ±1 of the violet system, electronic transition B 2 Σ + -X 2 Σ + ) also appeared. Unlike the cases reported in [7][8][9], the band was not observed in the…”

“…This finding indicates the presence of C 2 molecules from the very beginning of development of the laser plume. Thareja KUZYAKOV et al . et al [8] accounted for the formation of C 2 near the surface by the occurrence of the reaction C + C + M + M', where M is a third body (atom, molecule, cluster, etc.) involved in collisions.…”

Early stage expansion and time-resolved spectral emission of laser-induced plasma from polymer

“…The initial increase of emission intensity from CN molecules indicates the contribution from the recombination between atomic or molecular carbon in the plasma and nitrogen molecules in air. Such recombination has been observed in different circumstances [11,[15][16][17][18][19]. Recombination time constant of several hundreds of nanoseconds can be well fitted by considering involved chemical reactions C 2 + N 2 !…”

CN and C2 vibrational spectra analysis in molecular LIBS of organic materials

“…However, by considering this point, some works [32][33][34] state that the following recombination is an important process in C 2 formation: and because of absence of C 2 emission in urea and thiourea spectra in our experiment, in order to evaluate the occurrence of reaction (4) and clarify the main reason for the absence C 2 emission in spectra of samples which do not contain C-C bonds, we will present the LIB spectra of urea and thiourea in different ambient atmospheres in the next section.…”