Preparation of pure nano-grained Si2N2O ceramic

Pure Si2N2O ceramic is fabricated by nitridizing a powder mixture of Si and SiO2. Results show that the prepared Si2N2O is composed of nano-particles with a size of about 50 nm. Analysis and discussion are focused on the formation mechanism of the nano-grained Si2N2O ceramic based on thermodynamics calculation, micro-morphologies and phase composition analysis. Preferential formation of Si3N4 on the surface of nano-SiO2 particles at below melting point of Si and then successive in-situ transformation of SiO2 and Si3N4 into Si2N2O at above melting point of Si are considered as the key reasons to form the pure nano-grained Si2N2O ceramic.

► Pure Si2N2O ceramic was fabricated by nitridizing powder mixture of Si and SiO2.
► The prepared Si2N2O is composed of nano-particles with a size of about 50 nm.
► Formation mechanisms of the pure nano-grained Si2N2O ceramic were discussed.