Femtosecond laser ablation enables nanoparticle films useful in Raman spectroscopy
Researchers in the Journal of Applied Physics have studied the properties of femtosecond laser ablation plumes to better understand how to apply them to specialized films. The nanoparticle silver and gold films made by pulsed laser deposition are useful for optical applications such as surface-enhanced Raman spectroscopy. And nanoparticle films of transition metals such as iron, nickel or cobalt may be used to catalyze the growth of carbon nanotubes.
Salvatore Amoruso at the University of Naples (Italy) and colleagues examined the expansion dynamics of various ultrashort laser ablation plumes and the basic properties of the complicated ablation process in which some material is vaporized in the form of plasma and some in the form of nanoparticles. The team studied the shapes of both the plasma and nanoparticle plumes, which are important for pulsed laser deposition of nanoparticle films.
"We can understand our results in terms of some existing models of plume expansion," says co-author James Lunney at Trinity College (Dublin, Ireland). "We also see evidence that the pressure in the plasma plume has an influence on the expansion of the nanoparticle plume. Analysis of these expansion dynamics may also improve our physical understanding of the overall ablation process."
Source: Journal of Applied Physics
Posted by Lee Mather
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