Laser ablation of graphite in different buffer gases

Conference · Sun Oct 10 00:00:00 EDT 1993 · AIP Conference Proceedings (American Institute of Physics); (United States)

OSTI ID:5358492

Puretzky, A A ^[1]; Geohegan, D B; Haufler, R E; Hettich, R L; Zheng, X; Compton, R N ^[2]

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1. Institute of Spectroscopy, Russian Academy of Sciences, 142092 Troitsk, Moscow (Russian Federation)
2. Oak Ridge National Laboratory, Oak Ridge, Tennessee (United States)

The KrF-laser ablation of graphite into 300 Torr of He, Ne, Ar, and Xe has been studied by fast imaging of the plasma emission and post-deposition analyses of collected film deposits. In each case, the soot which was redeposited on the irradiated rod following ablation was highly fullerene-deficient compared to the material collected on the sample disk 1.5 cm from the rod, as determined by laser desorption Fourier Transform Mass Spectrometry (FTMS). Investigation of the plasma plume propagation using fast ICCD photography reveals three main phases to the expansion: (1) forward motion, deceleration and stopping of the leading edge of the plume, (2) an apparent reflected shock within the plume which propagates backward and reflects from the rod surface, (3) coalescence of these two components, resulting in continued expansion and dissipation of the plasma and the appearance of glowing ultrafine particles. For the laser plume propagating in 300 Torr of Xe the characteristic time intervals for these three phases are 0--300 ns, 300--1000 ns, and 1--1000 [mu]s for phases (1), (2), and (3) respectively. The possible explanation of the observed difference in fullerene content is discussed on the basis of different plasma phases resulting in soot deposition on the rod and sample disk. The measurement of ro-vibrational spectra of electronically excited C[sub 2] has been performed. Rotational and vibrational temperatures, T[sub R]=3000[plus minus]300 K and T[sub V]=6000[plus minus]500K have been obtained from the comparison of measured and calculated C[sub 2]-Swan band emission.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5358492
• Report Number(s): CONF-9304144-; CODEN: APCPCS; TRN: 94-005394
• Journal Information: AIP Conference Proceedings (American Institute of Physics); (United States), Vol. 288:1; Conference: 2. international conference on laser ablation: mechanisms and applications, Knoxville, TN (United States), 19-22 Apr 1993; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
GRAPHITE
ABLATION
LASER-PRODUCED PLASMA
PLASMA DIAGNOSTICS
EXCITED STATES
FOURIER TRANSFORMATION
FULLERENES
LASER RADIATION
MASS SPECTRA
PULSED IRRADIATION
THIN FILMS
CARBON
ELECTROMAGNETIC RADIATION
ELEMENTAL MINERALS
ELEMENTS
ENERGY LEVELS
FILMS
INTEGRAL TRANSFORMATIONS
IRRADIATION
MINERALS
NONMETALS
PLASMA
RADIATIONS
SPECTRA
TRANSFORMATIONS
360601* - Other Materials- Preparation & Manufacture
665000 - Physics of Condensed Matter- (1992-)