Subject: Applied Physics 2

Topic: Nano science And Nanotechnology

Difficulty: Medium

To produce nanoparticles of small identical size various methods are used: - • Sol gel method

• Inert gas condensation

• Chemical vapor decomposition

• Electrodeposition

• Plasma arching

• Mechanical alloying

RF Plasma Technique: It consists of an evacuated chamber and it is wound by high voltage Radio Frequency coils. The starting metal is placed in a container inside the evacuated chamber. To collect the nanoparticles, a cold rod is placed as shown in the figure below. The starting metal from which the nanoparticle is to be formed is placed in metal container. The RF coil is switched on and heat is produced. This heat is very high and metal is evaporated. Now the Helium gas is allowed to pass through the molten metal. At this juncture, the metal vapor settles on He gas atom and it diffuse up toward the colder collector rod. Thus, the nanoparticles are slowly deposited over the collector rod and hence nanoparticles are produced.