Micro-pulling-down

The micro-pulling-down (μ-PD) method is a crystal growth technique based on continuous transport of the melted substance through micro-channel(s) 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 (but generally different) velocity.

Crystallization
Fundamentals
Crystal Crystal structure Nucleation
Concepts
Crystallization Crystal growth Recrystallization Seed crystal Protocrystalline Single crystal
Methods and technology
Boules Bridgman–Stockbarger method Van Arkel–de Boer process Czochralski method Epitaxy Flux method Fractional crystallization Fractional freezing Hydrothermal synthesis Kyropoulos method Laser-heated pedestal growth Micro-pulling-down Shaping processes in crystal growth Skull crucible Verneuil method Zone melting
v t e

Many different types of crystal are grown by this technique, including Y₃Al₅O₁₂, Si, Si-Ge, LiNbO₃, α-Al₂O₃, Y₂O₃, Sc₂O₃, LiF, CaF₂, BaF₂, etc.^[1][2]

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:^[3]

• Charging of the crucible with starting materials (mixture of powders)
• 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 (including the crystal and the crucible) to room temperature

See also

• Crystal growth
• Czochralski process
• Float-zone silicon
• Flux method
• Laser-heated pedestal growth
• Shaping processes in crystal growth
• Verneuil process

• Lithium niobate
• Sapphire
• Scandium(III) oxide
• Yttrium aluminium garnet