Accessing the fractal dimension of free clusters in supersonic beams

作者：Mazza T; Devetta M; Milani P; Bongiorno G; Coreno M; Piseri P^*

来源：New Journal of Physics, 2011, 13(2): 023009.

DOI：10.1088/1367-2630/13/2/023009

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 lower-temperature conditions characterize the growth environment.

• 出版日期2011-2-2