Si 2 N 2 O is considered as a new great potential structural/functional candidate in place of Si 3 N 4 . The amorphous Si 3 N 4 nanopowder was incorporated into silica sol by adding of MgO and Y 2 O 3 as sintering aid. Synthesized powders were heated by spark plasma sintering at a heating rate of 100 o C/min yielded fully dense compacts at 1550 and 1750 o C for 40 min. The phase formation of samples was characterized by X-ray diffraction technique and Raman spectroscopy. The microstructure was studied by field emission scanning electron microscopy equipped by energy dispersive X-ray spectroscopy. Optical emissivity of Si 2 N 2 O phase was investigated by photoluminescence spectroscopy. The obtained results confirm that employing MgO in compare to the Y 2 O 3 could promote the fabrication of a fully dense pure Si 2 N 2 O specimen by at much shorter time than conventional sintering. Si 2 N 2 O have a strong, stable blue emission band centered at 455 nm with excitation wavelengths of 240 nm.. Keywords: Si 2 N 2 O, Spark plasma sintering, reaction sintering, Optical emittion.
