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uses
Hafnium is used to make control rods for nuclear reactors because of its
ability to absorb neutrons (its thermal neutron absorption cross section is
nearly 600 times that of zirconium), excellent mechanical properties and
exceptional corrosion-resistance properties.
Other uses:
* In gas-filled and incandescent lamps, for scavenging oxygen and nitrogen,
* As the electrode in plasma cutting because of its ability to shed electrons
into air,
* and in iron, titanium, niobium, tantalum, and other metal alloys.
* A hafnium-based compound is a candidate for High-K gate insulators in future
generations of integrated circuits. Intel and IBM in a partnership through
separate laboratory tests found that certain hafnium alloys can be used as a
more effective insulator than silicon dioxide and is planning to use the element
to produce faster and more energy efficient chips, by allowing circuitry scaling
to be reduced to less than 45 nanometers.
* DARPA has been intermittently funding programs in the US to determine the
possibility of using a nuclear isomer of hafnium (the above mentioned Hf-178-m2)
to construct small, high yield weapons with simple x-ray triggering
mechanisms—an application of induced gamma emission. That work follows over two
decades of basic research by an international community into the means for
releasing the stored energy upon demand. There is considerable opposition to
this program, both because the idea may not work and because uninvolved
countries might perceive an imagined "isomer weapon gap" that would justify
their further development and stockpiling of conventional nuclear weapons. A
related proposal is to use the same isomer to power Unmanned Aerial Vehicles,
which could remain airborne for weeks at a time.
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