Morphological control of tungsten-assisted β-Si _3N _4 nanowhiskers: Synthesis, mechanical and photoluminescence properties

摘要

One-dimensional β-Si _3N _4 rod-like crystals, aligned whiskers and nanowires have been self-assembly synthesized by SHS process respectively. Morphologies of the β-Si _3N _4 crystals varied from rods to aligned whiskers and nanowires by using tungsten powders as catalysts. Results demonstrated that tungsten powders play a significant effect on the growth of the anisotropic β-Si _3N _4 crystals, and the particle size of tungsten powders determines the diameters of the whiskers and nanowires. Elastic bending modulus of individual whiskers was measured by in situ TEM process, the average value of elastic bending modulus of individual as-synthesized whiskers was 488 GPa. The photoluminescence study of nanowires confirmed a good crystalline structure.