Synthesis of Silicon Nitride by a Combustion Reaction under High Nitrogen Pressure

Fine Si 3 N 4 powders were prepared by the combustion reaction of an Si powder compact undez 10 MPa nitrogen pressure. Addition of Si 3 N 4 powder to the starting Si promoted conversion of the reactants to homogeneous Si 3 N 4 particles. Submicrometer SisN 4 powders with a uniform size distribution around 0.5 μm were obtained from a 1.8Si‐0.4Si 3 N 4 mixture (molar ratio); they were free of residual Si.