纳米Si3N4制备及光学特性研究

为了制备高纯度的非晶纳米氮化硅粉体,在传统的激光诱导化学气相沉积法反应装置的基础上,加入正交紫外光束以激励NH3分解,从而提高气相中n(N)/n(Si)比,减少产物中游离硅的摩尔浓度.利用TEM技术和光谱分析技术研究了粒子的形貌和特性.结果表明:在一定的工艺参数条件下,可制备出粒径超微(7～15 nm)、无团聚、理想化学剂量(n(N)/n(Si)=1.314)的非晶纳米氮化硅粉体;表面效应和量子尺寸效应导致粉体红外吸收光谱和拉曼光谱的"蓝移"和"宽化"现象;采用双光束激励的激光诱导化学气相沉积法是制备高纯度纳米氮化硅粉体的理想方法.

Preparation of silicon nitride nano-powder and its optical characteristics

In order to synthesize amorphous silicon nitride nano powder of high purity, an perpendicular ultraviolet beam of light is added to the traditional laser induced chemical vapor deposition equipment. The NH3 molecules photondissociated and the n(N)/n(Si) ratio increased as the concentration of dissociated Si atoms decreased. The powders were investigated by TEM and spectrum analysis technology. It is demonstrated that the powders possess the following characteristics; high purity, ideal stoichiometry (n(N)/n(Si) = 1.314) and an narrow range of size (7 - 15 nm). The "Blue Shift" and "Widening" in the Infrared spectra and Raman spectra were observed, which was considered to result from the surface effect and quantum size. The laser induced chemical vapor deposition method with double beam optical stimulation is a preferable way to synthesize silicon nitride nano-powder of high purity.