Forget
the sleek aluminum case of the iPhone or the magnesium alloy used in
HTC's smartphone. The new hot thing is metal made out of cement. That's
right, cement:
In a move that would make the
Alchemists of King Arthur's time green with envy, scientists have
unraveled the formula for turning liquid cement into liquid metal. This
makes cement a semi-conductor and opens up its use in the profitable
consumer electronics marketplace for thin films, protective coatings,
and computer chips. [...]
This change demonstrates a unique way to make metallic-glass material,
which has positive attributes including better resistance to corrosion
than traditional metal, less brittleness than traditional glass,
conductivity, low energy loss in magnetic fields, and fluidity for ease
of processing and molding. Previously only metals have been able to
transition to a metallic-glass form.
Cement does this by a process called electron trapping, a phenomena
only previously seen in ammonia solutions. Understanding how cement
joined this exclusive club opens the possibility of turning other solid
normally insulating materials into room-temperature semiconductors.
[...]
The team of scientists studied mayenite, a component of
alumina cement made of calcium and aluminum oxides. They melted it at
temperatures of 2,000 degrees Celsius using an aerodynamic levitator
with carbon dioxide laser beam heating. The material was processed in
different atmospheres to control the way that oxygen bonds in the
resulting glass.
No comments:
Post a Comment