NOVELTY - Making particles, involves: (a) preparing a salt solution; (b) generating precursor droplets from the salt solution; (c) introducing axially the droplets into a microwave plasma torch (3); (d) entraining the droplets using gas flows towards a microwave generated plasma; (e) exposing the droplets to high temperature within the plasma; (f) controlling the residence time of the droplets in the plasma; (g) controlling quenching rates of the exhaust gas in a gas chamber; (h) filtering the exhaust gas of the plasma; and (i) extracting particles from the exhaust gas.    USE - The method is useful for making particles using a microwave generated plasma (all claimed). The produced particles are useful as an active material for lasers or phosphors, catalysts, infrared transmitting material, transparent armor, thermal barrier coating, and solid oxide fuel cells.    ADVANTAGE - The method is capable of efficiently making the particles directly from solution precursor droplets by a fast pyrolysis process using microwave generated plasma. The produced particles have uniform sizes and uniform thermal history, and improved mechanical, optical, and thermal properties.    DETAILED DESCRIPTION - Making particles using a microwave generated plasma, involves: (a) preparing a salt solution in water, in organic solvent, or in a mixture of water and organic solvent; (b) generating precursor droplets from the salt solution using a feed injection device; (c) introducing axially the precursor droplets into a microwave plasma torch (3); (d) entraining the precursor droplets using gas flows towards a microwave generated plasma; (e) exposing the precursor droplets to high temperature within the microwave generated plasma; (f) controlling the residence time of the precursor droplets in the microwave plasma; (g) controlling quenching rates of the exhaust gas in a gas chamber; (h) filtering the exhaust gas of the microwave generated plasma; and (i) extracting particles from the exhaust gas.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of an apparatus used for making particles using a microwave plasma.    Microwave radiation generator (1)    Plasma chamber (2)    Dielectric sheathing plasma torch (3)    Droplet maker (4)    Gas flow communication scheme. (5)