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AssigneeSumitomo Electric Industries, Ltd.
InventorsJin-Joo Park, Atsushi Kimura, Koji Yamaguchi, Akira Yamakawa
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The invention relates to material silicon nitride powder used for production of silicon nitride ceramics products. Provided herein is a material powder which can offer a compact having a homogeneous packing structure of the powder with good reproducibility and also to provide a method for producing the same. According to the method, a silicon nitride powder is heat treated in two-stage processing, one stage in an inert gas or reducing atmosphere at 100.degree. C.-1000.degree. C. for 5-600 min., and another stage in an oxidizing atmosphere at 300.degree. C.-1200.degree. C. for 5-600 min. As a result of this treatment, a silicon nitride powder is obtained in which its powder particles are crystalline in their interior and are coated with an amorphous layer having a 1-10 nm surface thickness and composed mainly of Si, N, O, and H, an atomic number ratio of oxygen to nitrogen (O/N) of the surface layer being within a range of 0.1-2.0.
A silicon nitride powder comprising powder particles which are crystalline in their interior and coated on their surfaces with a 1-10 nm thick amorphous layer composed mainly of Si, N, O, and H, and having an atomic number ratio of oxygen to nitrogen (O/N) in a surface layer of within a range of 0.1-2.0.
Dependencies are inferred from the claim text.