PROCESS AND DEVICE FOR OBTAINING UNFISSURED CRYSTALS

摘要

The invention relates to a process for obtaining unfissured crystals after the crystal has been formed by directional solidification from a melt in a quartz crucible and the crystal and the crucible are still at a temperature above 300 DEG C. The aim of the invention is to provide a process providing an unfissured fully drawn crystal. To this end, for its destruction, the quartz crucible is immersed in a molten silicate-forming hydroxide compound which is at a temperature of some 450 to 600 DEG C. NaOH or KOH may be used, for example, as the hydroxide compound.