Synthesis of nitrides and silicon carbide using sodium

Studies on the synthesis of nitrides, nitride-related compounds and silicon carbide by using Na as a flux and reaction enhanced medium are reviewed. Using a Na melt, ternary and quaternary nitrides and nitride-related compounds containing Ba and Sr were prepared at around 1000 K and N₂ pressure below about 10 MPa. Crystal growth of a binary nitride GaN by heating Ga and N₂ with Na was also found during the studies of the multinary compounds. AlN powder was prepared above the Al melt-ing temperature of 932 K. Single crystals of CrN and Mn₂N were obtained by heating Cr and Mn with a Na-Ga flux and a Na-In flux, respectively. β-type SiC powder and porous bulks were prepared by reaction of Si and fullerene with Na or Si and amorphous carbon with Na at 1000 K. The role of Na in the formation of the nitrides and silicon carbide is herein discussed.