Study on the Interaction between the Laser-Ablated Aluminum Plume and the Nitrogen Discharge Plasma by Time- and Space-Resolved Spectroscopy

Pulsed discharge of nitrogen was shown to be a very effective means to generate atomic nitrogen whose reactivity favored the synthesis of nitrides. In order to form aluminum nitride, such a plasma was allowed to interact with the plume generated by pulsed-laser ablation of aluminum. The plasma reaction was studied by time- and space-resolved optical emission spectroscopy. Emissions from ionic species of nitrogen (N⁺ and N₂⁺) in the reaction region were observed. They were believed to be excited by the shock front generated by the pulsed-laser ablation. The delay time between ablation and discharge could be tuned to maximize the N emission. That condition also produced the purest aluminum nitride powders.