162 nature materials | VOL 10 | MARCH 2011 | www.nature.com/naturematerials
interview
How did you get interested in a career ■■
in science?
I first got interested in science when I was
maybe a teenager. I guess like most teenagers
I gravitated to the things I seemed to do
best at high school. I enjoyed chemistry
and physics, and I guess in England in the
1960s once you start down that track you’re
funnelled more and more into a narrower
and narrower career path. I don’t say this
as a negative. I still had a wide range of
options until I went to university. But then
I studied metallurgy at Sheffield University
and apparently had a very good aptitude for
doing that, so I went on to graduate school
and the rest is history.
What is your research background ■■
in metallurgy?
I studied imperfections in crystals. My first
research topic in graduate school was on
radiation damage, so I studied point defects
and how they interact with grain boundaries.
Since then I’ve spent most of my career
studying interfaces of various kinds, mostly
grain boundaries. It varied across a whole
range of different things from deformation of
thin films to phase transformations.
since 2008, you have been the director ■■
of ames laboratory. What are your
priorities as a director?
To keep the Ames Lab at the forefront of
materials research. Ames Laboratory is a
very small national lab; it is actually the
smallest of all the DOE national labs. It is
a single-mission lab, so we are an Office of
Science lab, primarily operating with funding
from what’s called the Office of Basic Energy
Sciences. And within that we have a very
large focus on materials and catalysts.
ames lab started out with nuclear ■■
research?
That’s right. Historically, the lab started
out providing uranium for the Manhattan
project. That process was then extended to
other metals, in particular the rare earths. We
have for many years maintained the ability
to purify rare earths from oxides, and to this
day we have an operation that continues
doing that. It provides the purest rare-earth
samples available anywhere in the world.
That has enabled us to do a lot of work on
rare-earth magnets of various kinds — not
necessarily only high-field magnets, which
is an area of great topical interest, of course,
but magnets that have slightly more unusual
properties, such as extreme magnetoelastic
or magnetocaloric effects. We also use rare
earths as components of complex alloys. A
lot of intermetallics containing rare earths are
fabricated and studied here. Rare earths are
also used as dopants in superconductors, and
we currently have a very active programme
on the iron arsenide superconductors.
How do you see the situation on the ■■
limited availability of rare earths?
In some ways it is very straightforward,
and in some ways it is very complex. The
straightforward part is that the worldwide
demand for rare earths is increasing and
the supply is not growing at the moment.
It is made a little worse by the fact that all
the supply is in one place: 97% of the supply
is in China. Without making any political
statements or raising any concerns about
motives, if there is only one supplier there
is always concern. But the demand has
been going up, at least for materials like
neodymium, because neodymium iron
boron is the permanent magnet of choice for
applications where high magnetic fields are
desirable. That includes the motors that are
used in hybrid and electric vehicles, which
are growing immensely in popularity. And
they’re also used in the generators in wind
turbines, and certainly where I live, in the
middle of Iowa, we see the development of
wind-generated electricity going on at an
incredible rate. The Toyota Prius, which
is probably the most popular of all of the
hybrid vehicles today uses I think 1 kg of
neodymium per car, and a wind turbine
uses about 300 kg. These are large quantities,
and what’s happened is that the demand
for neodymium has gone up very rapidly
and the world’s supply has not been able
to keep pace. So the price goes up, and in
China, where they have the supply, they
are very concerned about retaining enough
neodymium to meet their own industrial
needs, which are growing faster than
anybody else’s in the world. What they’ve
been doing is, as you might expect, allowing
the price to rise. They have been restricting
exports of low-value-added products and
stressing the export of higher-value-added
products. Where they used to export raw ore
that other people would purify, they moved
to exporting only purified rare-earth oxides.
They now are moving away from allowing
the export of rare-earth oxides to pure metal,
and moving up the value chain from pure
metal to magnetic alloys, and from there to
fabricated magnets, and from there even to
completed motors, generators and so on. The
projections are that China’s needs for rare
earths will absorb all or very nearly all of
what they are able to produce in the coming
years, and the rest of the world’s needs will
have to be supplied in other ways. In the
last calendar year, 2010, the price of some
of the rare earths has gone up by 400–500%.
And that has made it attractive to open new
mines or reopen old mines that were not
economically viable five years ago when the
price of rare earths was very low.
in the united states, there is the ■■
mountain Pass mine in California?
That’s right. Molycorp is just about to begin
production of rare earths at its Mountain
Purveyor of the rare
The critical shortage of rare-earth elements is a concern for a number of important technologies, but
also an opportunity to research alternative materials and technologies, says Alexander King, director of
the US Department of Energy’s Ames Laboratory.
©
A
m
ES
L
A
bo
rA
To
ry
nmat_2973_MAR11.indd 162 7/2/11 16:15:38
© 2011 Macmillan Publishers Limited. All rights reserved