BUFFALO, N.Y. -- Few modern materials have achieved the fame of
silicon, a key element of computer chips and the namesake for
Silicon Valley, home to some of the world's most prominent
The next generation of computers, however, may not rely so much
University at Buffalo researchers are among scientists working
to identify materials that could one day replace silicon to make
computing faster. Their latest find: A vanadium oxide bronze whose
unusual electrical properties could increase the speed at which
information is transferred and stored.
Functional Materials, the research team reports that they have
synthesized nanowires made from vanadium oxide and lead.
The reason that these nanowires are so special is that they
perform a rare trick: When exposed to an applied voltage near room
temperature, the wires transform from insulators that are resistant
to carrying electricity to metals that more readily conduct
Each of these two states -- insulator and metal -- could stand
for a 0 or 1 in the binary code that computers use to encode
information, or for the "on" and "off" states that the machines use
to make calculations.
"The ability to electrically switch these nanomaterials between
the on and off state repeatedly and at faster speeds makes them
useful for computing," said study co-author Sambandamurthy
Ganapathy, a UB associate professors of physics.
"Silicon computing technology is running up against some
fundamental road blocks, including switching speeds," added
Sarbajit Banerjee, another co-author and a UB associate professor
of chemistry. "The voltage-induced phase transition in the material
we created provides a way to make that switch at a higher
As with other nanomaterials, the health and environmental
impacts of the nanowires would have to be investigated before their
widespread use, especially since they contain lead, Banerjee
Banerjee and Ganapathy oversaw the study, which appeared online
Aug. 17 in the journal Advanced Functional Materials. UB chemistry
PhD student Peter Marley was lead author. Other contributors
include Peihong Zhang, a UB associate professor of physics, and
students from Ganapathy's research group.
One intriguing characteristic of the material they synthesized
is that it only exhibits valuable electrical properties in
nano-form. That's because nanomaterials often have fewer defects
than their bulkier counterparts, Banerjee and Marley explained.
In the case of the lead vanadium oxide nanowires, the wires'
distinctive structure is crucial to their ability to switch from an
insulator to a metal.
Specifically, in the insulator phase, the position of the lead
in the nanowires' crystalline structure induces pools of electrons
to gather at designated locations. Upon applying a voltage, these
pools join together, allowing electricity to flow freely through
them all and transforming the material into a metal.
"When materials are grown in bulk, there's a lot of defects in
the crystals, and you don't see these interesting properties,"
Marley said. "But when you grow them on a nanoscale, you're left
with a more pristine material."
The study was funded by the National Science Foundation and the
Research Corporation for Science Advancement.