Procedure for growth of single crystals.
The sample material is contained in a crucible that can be moved along a temperature gradient. First, the sample material is melted and subsequently it is either slowly removed from the furnace, or the temperature of the furnace is gradually reduced. In both cases, the growth front of the monocrystal slowly advances in bottom-up direction through the crucible. Due to the convex form of the solidification border, selection of crystal “seeds” can be achieved so that after a few millimeters a single monocrystal is obtained.
Other procedures for growth of single crystals: