In this paper a method for the quantitative determination of a morphology descriptor of free clusters with complex nanostructure is presented and applied to transition metal nanoparticles produced by a pulsed vaporization source. The method, which is based on the low-pressure aerodynamic mobility of neutral particles, can be applied as a characterization tool to a broad class of gas-phase nanoparticle sources for on-line investigation of particle growth and for quantifying coalescence versus agglomerate aggregation. We report on the application of this method for the characterization of free titanium clusters produced by a pulsed microplasma cluster source in the size range of approximately 300-6000 atoms. The clusters have an open fractal-like structure, with the fractal dimension depending on their thermal history during growth and evolving towards softer aggregates for longer residence times where lowertemperature conditions characterize the growth environment.
|Titolo:||Accessing the fractal dimension of free clusters in supersonic beams|
DEVETTA, MICHELE (Secondo)
PISERI, PAOLO GIUSEPPE CARLO (Ultimo)
|Settore Scientifico Disciplinare:||Settore FIS/03 - Fisica della Materia|
|Data di pubblicazione:||2011|
|Digital Object Identifier (DOI):||10.1088/1367-2630/13/2/023009|
|Appare nelle tipologie:||01 - Articolo su periodico|