PREPARATION OF MAGNESIUM NITRIDE POWDER BY LOW-PRESSURE CHEMICAL-VAPOR-DEPOSITION

Submicrometer-scale magnesium nitride (Mg3N2) powder was prepared by l ow-pressure chemical vapor deposition, i.e., the reaction of Mg vapor with mixed NH3-N2 gases at 800-degrees-C under a pressure of approxima tely 1 kPa. The mixing ratios of NH3-N2 gases were 0% NH3-100% N2 (pur e N2), 20% NH3-80% N2, 40% NH3-60% N2, 60% NH3-40% N2, 80% NH3-20% N2, and 100% NH3-0% N2 (pure NH3). The reactions between Mg vapor and NH3 -N2 gases produced platy Mg3N2 particles <0.2 mum and acicular particl es with long-axis length of approximately 0.2 mum, whereas the reactio n of Mg vapor with pure NH3 gas produced spherical Mg3N2 particles wit h diameters of approximately 0.1 mum.