YORKTOWN HEIGHTS, N.Y.--(BUSINESS WIRE)--June 25, 2003--Scientists
from Columbia University, IBM and the University of New Orleans today
announced a new, three-dimensional designer material assembled from
two different types of particles only billionths of a meter across.
In the June 26 issue of the scientific journal Nature, the team
describes the precision chemistry methods developed to tune the
particles' sizes in increments of less than one nanometer and to
tailor the experimental conditions so the particles would assemble
themselves into repeating 3-D patterns.
Designing new materials with otherwise unattainable properties,
sometimes referred to as "metamaterials," is one of the promises of
nanotechnology. Two-dimensional patterns had previously been created
from gold nanoparticles of different sizes and mixtures of gold and
silver. Extending this concept to three dimensions with more diverse
types of materials demonstrates the ability to bring more materials
together than previously realized.
"What excites us the most is that this is a modular assembly
method that will let us bring almost any materials together," said
Christopher Murray, manager of nanoscale materials and devices at IBM
Research. "We've demonstrated the ability to bring together
complementary materials with an eye to creating materials with
interesting custom properties."
Murray worked with Stephen O'Brien, assistant professor of applied
physics and applied mathematics at Columbia University; Franz Redl, a
postdoctoral researcher affiliated with both Columbia and IBM; and
Kyung Sang Cho, a post-doctoral researcher affiliated with IBM and
supported by the Advanced Materials Research Institute of the
University of New Orleans. The work was supported in part by the
National Science Foundation, the independent agency that supports
basic research in all fields of science and engineering, through the
Center for Nanostructured Materials at Columbia University and by the
Defense Advanced Research Agency (DARPA) through programs on
metamaterials and advanced thermoelectric materials.
The scientists chose the materials for the experiments
specifically because of their dissimilar, yet complementary
properties. Lead selenide is a semiconductor that has applications in
infrared detectors and thermal imaging and can be tuned to be more
sensitive to specific infrared wavelengths. The other material,
magnetic iron oxide, is best known for its use in the coatings for
certain magnetic recording media.
The combination of these nanoparticles may have novel
magneto-optical properties as well as properties key to the
realization of quantum computing. For example, it might be possible to
modulate the material's optical properties by applying an external
"This was a demonstration of the ability to create such
materials," O'Brien said. "Given the unique combination of these
nanoscale materials, we're in uncharted territory with respect to the
properties, which we will be working on in the future."
The first step was to create the nanoparticles. The particle sizes
were calculated from the mathematical ideal of the structures they
wanted to create. In addition to fine-tuning the sizes, the particles
had to be very uniform, all within 5 percent of the target size. They
settled on iron oxide particles 11 nanometers in diameter, which were
created by Redl, and lead selenide particles 6 nanometers in diameter,
created by Cho. There are approximately 60,000 atoms in one of the
iron oxide nanoparticles and approximately 3,000 atoms in the lead
Next, Redl assembled the nanoparticles--or more to the point, had
the particles assemble themselves--into three different repeating 3-D
patterns by tailoring the experimental conditions. Forming these
so-called "crystal structures," as opposed to random mixtures of
nanoparticles, is essential for the composite material to exhibit
consistent, predictable behaviors. Various other materials are known
to assemble spontaneously into these structures of close-packed
particles, but none has been made of two components in three
dimensions and at the length scales reported in the Nature paper.
"The precise and energy-efficient self-assembly of matter into
material structures with properties that cannot be achieved otherwise
is an important goal for nanotechnology," said Mihail Roco, NSF senior
advisor for nanotechnology and chair of the National Science and
Technology Council's Subcommittee on Nanoscale Science and
Engineering. "This is just one way that nanotechnology will help
foster 'the next industrial revolution.'"
For related images and animations from today's announcement,
About the NSF Center for Nanostructured Materials, Columbia
The Columbia University Materials Research Science and Engineering
Center (MRSEC) is an interdisciplinary team of university, industrial,
and national laboratory scientists and engineers working together to
develop and examine new types of nanocrystals and ways of assembling
them into thin films.
About IBM Research
IBM Research is the information technology industry's largest
information technology research organization, with more than 3,000
scientists and engineers at eight labs in six countries.
For more information about IBM's nanotechnology research projects:
About The National Science Foundation
The National Science Foundation is an independent federal agency
that supports fundamental research and education across all fields of
science and engineering, with an annual budget of nearly $5.3 billion.
National Science Foundation funds reach all 50 states through grants
to nearly 2,000 universities and institutions. Each year, NSF receives
about 30,000 competitive requests for funding, and makes about 10,000
new funding awards. The National Science Foundation also awards over
$200 million in professional and service contracts yearly.
NSF Home Page:
CONTACT: Columbia University Joseph Kennedy, 212/854-9752 Email Contact or IBM My Luu, 914/945-2988 Email Contact or NSF David Hart, 703/292-7737 Email Contact