In-situ reactive synthesis of full dense Si2N2O by incorporating of Amourphous nanosized Si3N4;effect of MgO and Y2O3

Abstract

Si2N2O is considered as a new great potential structural/functional candidate in place of Si3N4. The amorphous Si3N4 nanopowder was incorporated into silica sol by adding of MgO and Y2O3 as sintering aid. Synthesized powders were heated by spark plasma sintering at a heating rate of 100 oC/min yielded fully dense compacts at 1550 and 1750 oC 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 Si2N2O phase was investigated by photoluminescence spectroscopy. The obtained results confirm that employing MgO in compare to the Y2O3 could promote the fabrication of a fully dense pure Si2N2O specimen by SPS at much shorter time than conventional sintering. Si2N2O have a strong, stable blue emission band centered at 455 nm with excitation wavelengths of 240 nm .