Synthesis of nanocrystalline magnesium nitride (Mg 3N 2) powder using thermal plasma

Abstract

Nanocrystalline magnesium nitride (Mg 3N 2) powder was synthesized from bulk magnesium by thermal plasma at atmospheric pressure. Magnesium vapor was generated through heating the bulk magnesium by DC plasma jet and reacted with ammonia gas. Injecting position and flow rates of ammonia gas were controlled to investigate an ideal condition for Mg 3N 2 synthesis. The synthesized Mg 3N 2 was cooled and collected on the chamber wall. Characteristics of the synthesized powders for each experimental condition were analyzed by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and thermogravity analysis (TGA). In absence of NH 3, magnesium metal powder was formed. The synthesis with NH 3 injection in low temperature region resulted in a formation of crystalline magnesium nitride with trigonal morphology, whereas the mixture of magnesium metal and amorphous Mg 3N 2 was formed when NH 3 was injected in high temperature region. Also, vaporization process of magnesium was discussed.