Slowing of femtosecond laser-generated nanoparticles in a background gas

Journal Article · Mon Nov 24 04:00:00 EST 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4902878· OSTI ID:22392072

Rouleau, C. M.; Puretzky, A. A.; Geohegan, D. B. ^[1]

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1. Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

The slowing of Pt nanoparticles in argon background gas was characterized by Rayleigh scattering imaging using a plume of nanoparticles generated by femtosecond laser through thin film ablation of 20 nm-thick Pt films. The ablation was performed at threshold laser energy fluences for complete film removal to provide a well-defined plume consisting almost entirely of nanoparticles traveling with a narrow velocity distribution, providing a unique system to unambiguously characterize the slowing of nanoparticles during interaction with background gases. Nanoparticles of ∼200 nm diameter were found to decelerate in background Ar gas with pressures less than 50 Torr in good agreement with a linear drag model in the Epstein regime. Based on this model, the stopping distance of small nanoparticles in the plume was predicted and tested by particle collection in an off-axis geometry, and size distribution analysis by transmission electron microscopy. These results permit a basis to interpret nanoparticle propagation through background gases in laser ablation plumes that contain mixed components.

• OSTI ID: 22392072
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 21 Vol. 105; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ARGON
LASERS
NANOPARTICLES
PLATINUM
RAYLEIGH SCATTERING
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY