Method for adjusting temperature field structure of growing CaF2 crystals, and apparatus thereof

The invention relates to a method for growing CaF2 crystals under vacuum conditions by adopting a descent technology, and an apparatus thereof. The effective control of the temperature field structure in a crucible is difficult to realize when the descent technology is adopted to grow CaF2 crystals with large diameter, so the method for adjusting the temperature field structure at a solid-liquid interface and the apparatus thereof are adopted to increase the adjustability of the temperature field at the solid-liquid interface in the crystal growth process in order to obtain a flat solid-liquid interface or upward dimpling-shaped solid-liquid interface required by the growth of high quality monocrystals. The apparatus comprises a graphite descent rod and a movable stainless steel water cooling rod positioned in the graphite descent rod. The temperature field structure at the solid-liquid interface in the crucible can be adjusted by continuously adjusting the relative position of the graphite descent rod and the stainless steel water cooling rod in the crystal growth process in order to make the solid-liquid interface maintain the flat interface or upward dimpling-shaped interface in the whole crystal growth process, so the internal stress in the growing crystals is effectively reduced, and the quality of the crystals is improved.