Synthesis of 2-Dimensional Aluminum Nitride Platelets with (002) Preferred Orientation

摘要

This paper presents a systematic investigation on the formation of two-dimensional (2-D) AlN plate powders from Al2O3 plate powders by a carbothermal reduction and nitridation (CRN) method. The AlN platelets with the preferred orientation of (002) formed at the low temperature of 1500 degrees C for 1 h. When the reaction was conducted at 1500 degrees C for more than 1 h or at a temperatures higher than 1500 degrees C, voids generated on the surface and resulted in the formation of small powders. Measurement of the diffusion lengths and coefficients shows that the mutual diffusion of oxygen and nitrogen for the plate powder is slower than that for the spherical powders, that is, there is a higher activation energy for the plate-shaped powder than for the spherical powder. Therefore, the control of diffusion of oxygen and nitrogen gases is a very important factor in the formation of 2-D AlN platelets.