Direct synthesis of AlN nano powder by dielectric barrier discharge plasma assisted high-energy ball milling

In this paper, a method of direct synthesis of aluminum nitride nano powder by dielectric barrier discharge assisted mechanical ball milling is presented. The mixtures of Al and LiOH·H₂O powders, as samples, treated by dielectric barrier discharge assisted mechanical ball milling are characterized by X-ray diffraction and scanning electron microscope. It is shown that AlN nano powders are generated in 1 h milling time and the powders present a loose lamellar structure in the irregular distribution. For a long milling time (6 h), the crystallite size decreases with the milling time increasing and reduces to about 40 nm. Also, to study the mechanism of direct synthesis of aluminum nitride assisted by plasma, the waveforms of discharge voltage and current, and optical emission spectra of active species are recorded. The main physiochemical processes of production of active species in DBD are discussed.