Methods Of Synthesis

Earlier in the chapter we described one method of making nanoparticles using laser evaporation in which a high intensity laser beam is incident on a metal rod, causing atoms to be evaporated from the surface of the metal. These metal atoms are then cooled into nanoparticles. There are, however, other ways to make nanoparticles, and we will describe several of them.

Figure 4.25 illustrates a method of nanoparticle synthesis that utilizes a plasma generated by RF heating coils. The starting metal is contained in a pestle in an evacuated chamber. The metal is heated above its evaporation point using high voltage RF coils wrapped around the evacuated system in the vicinity of die pestle. Helium gas is then allowed to enter the system, forming a high temperature plasma

98 properties of individual nanoparticles COLLECTOR ROD

CONTAINER With METAL--—

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