element 41 is niobium and I'd ever seen
niobium until recently and then I was
lent a medal I haven't won the medal but
it is a medal that is given each year to
somebody who's made a real contribution
to the field of niobium chemistry or
niobium science the medal is made out of
niobium so look carefully this is
metallic niobium I can't remember who
won it last year but it has been won by
a series of people mostly in the field
of metallurgy and I'll explain you why
it's metallic a rather than chemistry in
a minute
I was lent this by the company CBMM
which Awards this medal and together
with the Institute of materials and
minerals it is named after Charles
hatchet who was the English scientist
who discovered niobium or discovered the
element initially and is really quite
interesting it was at the beginning of
the 19th century just after the idea of
elements had been published so everybody
was looking for elements and Charles
hatchet looked at a mineral which had
been in a museum in London for quite a
long time a mineral that came from
America and he discovered a new element
and because it came from America he
called it columbium because Columbia
isn't the Latin name that is often used
for America and I think the name
columbium sounds really beautiful
normally really opposed to naming
elements after countries well I think
it's quite nice when it's named by
somebody who doesn't come from that
country then it's a genuine honor rather
than a patriotic gesture and of course
England had just lost the American
colonies so it was particularly a nice
gesture Hachette unfortunately didn't
continue as a chemist and he worked in a
company that made carriages I suppose
the modern equivalent
a sports car company and later in his
career he focused on the carriages
rather than on the science the element
was then rediscovered in Germany and
named niobium there was a problem
because the Americans called it
columbium the Europeans called it
niobium and there was a sort of trade
off it was agreed the Americans would
call it niobium if the Germans and the
Europeans would call wolfram tungsten so
everybody was happy but niobium is
actually a relatively abundant element
compared to many of the metals and that
by far the biggest deposit is in Brazil
where this company's CBMM is a mining
company that digs niobium out of the
ground now the main user for niobium at
the moment is in strengthening steel
steel for making bridges steel for
making cars steel for making pipelines
that you use for high-pressure gas like
natural gas so imagine this piece of
paper is steel if the steel was just a
single crystal if you put a force on it
like my pulling here it would be very
strong but actually the steel consists
of small so-called grains rather like
small crystals the boundary between the
grains is a weak point so let me
illustrate that by tearing the paper a
bit now you can see if I pull again when
there's this weak point it just pulls
apart very easily so the grain
boundaries is what causes the failure
and the pipe bursts if you don't make it
thick enough if you add just a tiny bit
of niobium to the steel less than 0.1 of
a percent less than one part in the
thousand the niobium concentrates along
the grain boundary and strengthens it
let me show you an analogy again so here
we've got our two grain
and you can see this weak point in
between but now if you imagine the
niobium across this grain boundary it
forms a block so that when you pull it
it's much stronger and it doesn't break
I'm pulling really hard what this means
is that if you add a small amount of
niobium to your pipe to the steel that
you make your pipe you can put a lot
more gas through the same pipe there's a
pipe in China which is eight thousand
kilometers long and by adding some
niobium and making that pipe a little
heavier one and a quarter times heavier
you can take two and a half times as
much gas down the same pipe in cars the
cars in developed countries like the US
and in Europe they add about 200 grams
of niobium to the steel that makes up
the car and that saves a hundred kilos
of weight of steel in that car it's
almost the weight of a whole passenger
and so then when you're driving every
hundred kilometers or so that you drive
that saves one or two litres of petrol
depending how aggressively you drive the
first out is adding niobium make the car
lighter weight it makes the car lighter
because the steel is stronger so you
don't need so much steel to make the
same strength car but you said the pipe
was made heavier in China that's because
of other things well you made it heavier
by little bit and then you could take
twice as much gas in it in the car you
just want to take the same number of
passengers so you can make it lighter
and take the same number of passengers
it's quite difficult to put just a small
amount of niobium into and the steel
it's rather like adding just a grain or
two of salt to your cooking so in fact
the producers of niobium producer
material which is called Ferro now
which is a mixture of iron and niobium
of which I've got some pieces here it
looks a bit black if you crack it open
and so this is the material that is
added to the mix when people are making
steel well I believe that some
metallurgists in America still call it
Colombian and I think that's rather nice
but it's not used as a name in chemistry
and in fact I think most chemists will
no longer have even know the name
existed I liked it it rolls off the
tongue so much nicer than some of the
modern names for elements that recently
discovered ones but it's also good
because it reminds one of the history
and I think the discovery of niobium or
columbium in a sample in the museum is a
very good reason why we need to preserve
things in museums because very often
scientists who come later can discover
things that the people who originally
collected the samples would never have
dreamt of the person who originally
collected the sample where nerubian was
discovered didn't know that elements
existed so there was the sample just
waiting for the future scientist to
discover this
all right yeah so the other application
for niobium is in that alloy with tin
which makes so-called superconducting
wire some wires when you cool it down to
very low temperature lose all their
electrical resistance so you can put
through a very big current without
heating up because the heat generated by
an electric current is related to the
resistance if the resistance is zero no
heating this means that you can make
very small and very powerful magnets
such are used for magnetic resonance
imaging and for some sorts of
accelerators like the Large Hadron
Collider at CERN niobium again has a
really quite important metallurgical
role I'm not a physicist I'm not sure
exactly why it is that niobium tin has
these superconducting properties but
they only happen at very low
temperatures so you need liquid helium
to cool them right down before you see
this behavior