Micro-pulling-down
The micro-pulling-down method is a crystal growth technique based on continuous transport of the melted substance through micro-channel made in a crucible bottom. Continuous solidification of the melt is progressed on a liquid/solid interface positioned under the crucible. In a steady state, both the melt and the crystal are pulled-down with a constant velocity.
Many different types of crystal are grown by this technique, including Y3Al5O12, Si, Si-Ge, LiNbO3,
α-Al2O3, Y2O3, Sc2O3,
LiF, CaF2, BaF2, etc.
Crystal growth routine
Standard routine procedure used in the growth of most of μ-PD crystals is well developed. The general stages of the growths include:- Charging of the crucible with starting materials
- Heating of the crucible until starting materials in the crucible are completely melted
- Upward displacement of the seed until its contact with the meniscus or crucible
- Formation of the meniscus and partial melting of the seed top
- Correction of the shape of the meniscus through appropriate adjustment of crucible temperature and position of the seed crystal
- Crystal growth through pulling of the seed in downward direction
- Separation of the as grown crystal from the meniscus
- Cooling of the system to room temperature