Self-Propagating High Temperature Synthesis of β-Si_3N4 Rod-like Crystals

β-Si3N4 rod-like crystals were fabricated under high nitrogen pressure by using the Self-propagating High-temperature Synthesis method. The effect of different amount of Y2O3 addition on the aspect ratio of β-Si3N4 rod-like crystals was studied. By using copper crucible absorbing the heat generated by the exothermic reaction to quench the reaction, the growth morphology of β-Si3N4 in the different stages of the reaction was observed. The reaction courses were also expounded. The results reveal that the optimum amount of Y2O3 addition is 2wt%-5wt%. Too much amount of Y2O3 addition could result in the inhomogeneous growth and distribution of the crystals. By considering the morphology of the products, the growth mechanisms of β-Si3N4 rod-like crystal are the results from the synergy of the VLS and VS.