NaSi was heated at various Na vapor pressures (p(Na) 0.1-1.2 atm) and temperatures (973-1173 K) to investigate the condition of Si crystal formation from NaSi by Na evaporation. Silicon single crystals 1-3 mm in diameter were grown by evaporation of Na from Na-Si melt at 1173 K and p(Na)=0.74 atm. (C) 2012 Elsevier B.V. All rights reserved.