Synthesis and characterization of magnesium nitride powder formed by Mg direct reaction with N2

Mg3N2 powder of high quality has been synthesized by the direct nitridation reaction of Mg powder with N2 gas in 1.0 l/min for 60 min at a temperature between 650 °C and 800 °C. Thermal gravimetric analysis (TGA) and differential thermal analysis (DTA) were employed to investigate the thermal nitridation behavior of Mg powder. X-ray diffraction (XRD) indicates that Mg3N2 powder has a cubic structure with a lattice constant a = 0.997 nm. The scanning electron microscopy (SEM) images of Mg3N2 powder show that Mg3N2 powder is of a rod-like structure. The Fourier transformed infrared (FTIR) spectra indicate a high quality of the Mg3N2 powder fabricated in this way.

Research highlights▶ Magnesium nitride (Mg3N2) powder of high quality has been synthesized successfully through the direct nitridation reaction of Mg powder with N2 gas in 1.0 l/min for 60 min at a nitridation temperature between 650 °C and 800 °C. The direct reaction between Mg powder and N2 is a valuable method used in large-scale industry. ▶ The TGA and DTA curves of Mg powder in Ar atmosphere show that the melting point of metal Mg is 650 °C. When the temperature is about 689 °C, some of the liquid state Mg will be vaporized into the gas state Mg. The higher the temperature is, the faster the vaporization rate is. The DTA and TGA curves of Mg powder in N2 atmosphere indicate that the initial thermal nitridation takes place at about 550 °C. The higher the temperature is, the faster the nitridation rate is. ▶ X-ray diffraction (XRD) indicates that Mg3N2 powder has a cubic structure with a lattice constant a = 0.997 nm, which is in good agreement with the published value (0.995 nm) recorded in the JCPDS document. ▶ The SEM images of Mg3N2 powder show that Mg3N2 powder is of a rod-like structure. At low temperatures there are clear edges and corners, which become smoother and smoother as the temperature increases. ▶ The Fourier transformed infrared spectra of Mg3N2 powder indicate a high quality of the Mg3N2 powder fabricated in this way.