Crystals
are grown by melting a rod of silicon or germanium, both important materials
in the manufacturing of computer components, and then cooling the rod under
carefully controlled conditions. The diagram at right (click on it for a
bigger view) illustrates the industrial method. Traditionally even the most
strict controls on laboratory environments could not prevent imperfections
and impurities from being generated in the final crystal. One option is
to grow these crystals in the near-zero-g environment of space, for example
aboard the space shuttle. This resulted in a significant improvement in
the quality of crystals that could be grown. However, spaceflight is an
expensive option, and growing time is limited. 
Using magnetic
fields in the laboratory, crystals have been grown under desirable conditions
that could only otherwise be obtained in space. Magnetic fields, however,
are limited in many ways as a simulator of reduced gravity one of which
being the size of crystals that can be grown. The combination of a low-gravity
environment in addition to the use of magnetic fields would help to overcome
this size limitation. Scientists at MSFC are working on a furnace (at left)
to be flown aboard the International Space Station that will combine the
benefits of a low-gravity environment and a strong magnetic field. 
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Headlinesreturn to Space Sciences Laboratory Home
Curator: Linda
Porter
NASA Official: Gregory S.
Wilson