Silicon Oxynitride Ceramics Prepared by Plasma Activated Sintering of Nanosized Amorphous Silicon Nitride Powder without Additives.

Si₂ N₂ O ceramics were prepared by plasma activated sintering using nanosized amorphous Si₃ N₄ powder without sintering additives within a temperature range of 1400°C-1600°C in vacuum. A mixed Si- N_{4− n}- O _n ( n = 0, 1...4) amorphous structure was formed in the process of sintering, and Si₂ N₂ O crystals were nucleated where the local structure was similar with Si₂ N₂ O. After sintering at 1600°C, the Si₂ N₂ O ceramic was composed of elongated plate-like Si₂ N₂ O grains and amorphous phase. The Si₂ N₂ O grains showed a width of less than 100 nm and a very high aspect ratio. [ABSTRACT FROM AUTHOR]