The effect of Mg(NO₃)₂ addition on the formation of AlN nanowire by direct nitridation

In this study AlN nanowire was produced via direct nitridation (DN) method. In order to investigate the effect of nitridation on the formation of nanowire, elemental aluminum powder and ammonium chloride (NH₄Cl) mixture was prepared with and without the addition of minor amount (0.5 wt%) of magnesium nitrate (Mg(NO₃)₂). The experiments were performed in a conventional electric resistance furnace coupled with a horizontal stainless-steel tube. Nitridation was carried out at 800–1000 °C for 2 h in N₂ atmosphere. Differential scanning calorimetry and thermal gravimetric analyses were performed to powder mixtures, in order to examine the effect of Mg(NO₃)₂ addition on the morphology of AlN nanowire. X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM) and Energy-dispersive X-ray spectroscopy (EDS) techniques were also performed to identify to formed phases after the DN method. Using this technique, it was shown that with an addition of Mg(NO₃)₂ at 950 °C in N₂ atmosphere a complete transformation to AlN nanowires was achieved having diameters of 40–45 nm.