TABLE OF CONTENTS The types of aerosol nanocrystal sources are many but most incorporate the same processing stages: evaporation of the bulk material, growth through collision-coalescence within a thermal gradient and, possibly, annealing and passivation before collection. The methods most have incorporated have taken into account one or another of the theoretical aspects presented previously. The choice of techniques presented will somewhat follow an historical order starting with the condensation of a material vapor in a low-pressure, inert, environment, (bell-jar method) followed by various modifications of this technique. The forced flow of a carrier gas to control the growth and cooling times of the material vapor will be presented next and will include the production of nanocrystals for immediate use in a mass spectrometer as cluster beams.
Arc or "spark" heating sources will then be presented along with growth of particles via chemical precursors in a flame or jet a la Windeler et al. (1997a). The later mentioned method does not necessarily incorporate all of the ideas presented above for an inert gas condensation source but is a wellstudied and efficient means of producing nano-sized particles of varying composition. Last will be a fairly broad overview of other methods of nanocrystal production in the gas-phase. Laser vaporization of the constituent material and pulsed ion sources will be shown. Finally, material evaporation using sputtering will be mentioned.
The original idea of synthesizing nanocrystals in a low pressure inert gas environment is mainly attributed to...
