Investigation of Sodium effect on synthesis of Si3N4 by using carbothermal reduction and nitridation process from MCM-48/Saccharose precursor

In this research, the effect of sodium additive on silicon nitride synthesis has been investigated via carbothermal reduction and nitridation procedures, by using MCM-48 silicate precursor, and saccharose as a carbon agent. In this study, at first mesoporouse silicate has been synthesised, and then binary mixture was prepared by solving MCM-48 and saccharose in deyonized water. In order to investigate the effect of sodium additives, triple systems were prepared by sodium additive (in 1, 2 or 3 weight percent range) in the same time with binary mixtures. Then in temperature of 1400°C nitridation were performed under nitrogen gas atmosphere. Characterization of physical and microstructural properties of mesoporouse silicate and silicon nitride samples performed by various techniques likely X- Ray Diffraction, Scanning Electron Microscopy and Transmission Electron Microscopy. Results shows adding sodium cause to decreasing of liquid phases creating temperature and covering MCM-48 surfaces with this phases and will be prevent the formation of silicon nitride. Also filling the pores with liquid phases cause to prevent the formation of porouse structure.