Preparation and mechanism of nanometer Al5O6N via shock wave plasma technique

Cubic Al5O6N nanocrystals were successfully synthesized via a novel strategy called shock wave plasma technique, using trinitrotoluene (TNT) and aluminum powder as raw materials and water as protection medium. The precursor including carbon and Al5O6N was engendered firstly during the detonation of compound dynamite, and then the pure Al5O6N nanoparticles were obtained when the carbon was removed through calcining at high temperature. The precursor and the final as-synthesized Al5O6N powder were characterized by X-ray diffraction (XRD), Raman spectrum and high-resolution transmission electron microscope (HRTEM), respectively. The calcining temperature schedule of the precursor was decided through DTA/TG analysis. The results indicate that the precursor consists of 37.7% carbon and 62.3 °C Al5O6N. After calcining at 600 °C for 1 h, the average diameter of the as-synthesized Al5O6N nanocrystal is 30–40 nm and the morphology micrograph takes on uniform spherical shape. The lattice parameters are consistent completely with the standard cubic Al5O6N (JCPDS 48-0686). The well-dispersed Al5O6N nanocrystals synthesized by shock wave plasma technique can be attributed to the covering of carbon and fast cooling of water medium. A possible reaction mechanism was also proposed preliminarily based on the experimental results.