AP01050 Highly-Pure Silicon Nitride Nanomaterial Prepared by Chemical Nitridation Method

Abstract

In this work, highly-pure silicon nitride nanopowders were prepared by chemical nitridation method. The tetraethyl orthosilicate (TEOS) was used as a precursor for silicon alkoxide while ammonia was used as a precursor for nitrogen. The structural characteristics of the prepared nanopowders were determined and studied as functions of annealing temperature carried out during the preparation method. The chemical method used in this work can be characterized by low cost, simple requirements, and reliability to produce highly-pure nanopowders. Results showed that the prepared nanopowders largely maintain an amorphous or highly nanocrystalline structure, even at 1100 °C. Significant crystallization into well-defined crystalline phases of Si₃N₄ does not occur under these annealing conditions. While the material remains nanostructured, annealing at higher temperatures (especially 1100 °C) leads to some degree of particle growth or rearrangement, even without full crystallization. The silicon (Si) and nitrogen (N) peak intensities remain largely consistent, indicating that the stoichiometry of Si₃N₄ is maintained. A small carbon is residual from the chemical nitridation process or atmospheric contamination. This impurity appears to be stable or present consistently across the different annealing temperatures. The chemical nitridation method, combined with annealing up to 1100 °C, primarily yields amorphous or highly nanocrystalline Si₃N₄ nanopowders. While higher temperatures promote some particle growth, they do not induce significant crystallization, and the overall elemental composition remains consistent with a minor carbon impurity.