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Space- and Ground-Based Crystal Growth Using a Baffle (CGB)
- Source :
- Microgravity Materials Science Conference 2000. 2
- Publication Year :
- 2001
- Publisher :
- United States: NASA Center for Aerospace Information (CASI), 2001.
-
Abstract
- The composition of semiconductor crystals produced in space by conventional melt-growth processes (directional solidification and zone melting) is affected by minute levels of residual micro-acceleration, which causes natural convection. The residual acceleration has random magnitude, direction and frequency. Therefore, the velocity field in the melt is apriori unpredictable. As a result, the composition of the crystals grown in space can not be predicted and reproduced. The method for directional solidification with a submerged heater or a baffle was developed under NASA sponsorship. The disk-shaped baffle acts as a partition, creating a small melt zone at the solid-liquid interface. As a result, in ground based experiment the level of buoyancy-driven convection at the interface is significantly reduced. In several experiments with Te-doped GaSb, nearly diffusion controlled segregation was achieved.
- Subjects :
- Solid-State Physics
Subjects
Details
- Language :
- English
- Volume :
- 2
- Database :
- NASA Technical Reports
- Journal :
- Microgravity Materials Science Conference 2000
- Notes :
- NRA-94-OLMSA-06
- Publication Type :
- Report
- Accession number :
- edsnas.20010057297
- Document Type :
- Report