Similar
to the massive forms
of chromium, aluminium
and titanium, nickel
is a very reactive
element, but is
slow to react in
air at normal temperatures
and pressures. Due
to its permanence
in air and its inertness
to oxidation, it
is used in coins,
for plating iron,
brass, etc., for
chemical apparatus,
and in certain alloys,
such as German silver.
Nickel
is magnetic, and
is very often accompanied
by cobalt, both
being found in meteoric
iron. It is chiefly
valuable for the
alloys it forms,
especially many
superalloys, and
particularly stainless
steel. Nickel is
also a naturally
magnetostrictive
material, meaning
that in the presence
of a magnetic field,
the material undergoes
a small change in
length.[4] In the
case of Nickel,
this change in length
is negative (contraction
of the material),
which is known as
negative magnetostriction.
