Low-temperature synthesis of Si and Si-based compounds using Na

Abstract

Low-temperature solution growth of Si crystals using Na was demonstrated based on the Na–Si binary phase diagram. Single crystals, films, porous bulk samples, and helical microtubes of Si crystals were prepared from a Na–Si solution by Na evaporation. Dissolution and crystallization of Si in a Na melt reduced the impurity content in the Si crystals. Low-temperature synthesis and morphology control of porous SiC ceramics using Na were also performed and a new ternary compound, Na₈B_74.5Si_17.5, was synthesized.