Acta Phys. -Chim. Sin. ›› 1995, Vol. 11 ›› Issue (10): 886-889.doi: 10.3866/PKU.WHXB19951006

• ARTICLE • Previous Articles     Next Articles

Study of Surfacial Structure of Nano Si3N4 by Fourier Infrared Diffusion Reflection Spectra

Li Ya-Li, Gao Yang, Liang Yong, Zheng Feng, Xiao Ke-Shen, Hu Zhuang-qi   

  1. State Key Laboratory of Rapidly Solidiffied Non-equilibrium Alloys;Micro crystalline and Laser Processing Department,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110015
  • Received:1994-11-16 Revised:1995-03-06 Published:1995-10-15
  • Contact: Li Ya-Li

Abstract:

 The surface structure, ambient oxidation and thermal stability of the lasersynthesized Si3N4 nano powders (15-30nm) with different compositions have been studied by Difusion Reflectin Infrared Fourier Transform (DRIFT) spectra. Results show that the nitrogen rich powders with a freshed surface have silazane structure (Si3-xNHx, x=1-3)and this silazane group reacts with water in the air to form silanol group (Si-OH). The amount of the silazane groups increases with the increase of the nitrogen content in the powders. The silicon rich powders have little silazane on powder surface and the oxidation of the powders occurs by the formation of Si-O bonds from the reaction between the surface Si atoms and the oxygen in the air. The silazane groups and the silanol groups are eliminated from the particle surface upon a vaccum annealing at temperature higher than 600 and 1500℃, respectively.

Key words: Infrared spectra, Si3N4, Surface