Scanning electron
micrograph of c-BN nanoneedles and microneedles up to three
microns in length.
Image credit: Anagh Bhaumik.
(February 4, 2016) Researchers
at North Carolina State University have discovered a new phase of the material
boron nitride (Q-BN), which has potential applications for both manufacturing
tools and electronic displays. The researchers have also developed a new
technique for creating cubic boron nitride (c-BN) at ambient temperatures and
air pressure, which has a suite of applications, including the development of
advanced power grid technologies.
“This is a sequel to our Q-carbon discovery and converting
Q-carbon into diamond,” says Jay Narayan, the John C. Fan Distinguished Chair
Professor of Materials Science and Engineering at NC State and lead author of a
paper describing the research. “We have bypassed what were thought to be the
limits of boron nitride’s thermodynamics with the help of kinetics and time
control to create this new phase of boron nitride.
“We have also developed a faster, less expensive way to
create c-BN, making the material more viable for applications such as
high-power electronics, transistors and solid state devices,” Narayan says.
“C-BN nanoneedles and microneedles, which can be made using our technique, also
have potential for use in biomedical devices.” C-BN is a form of boron nitride
that has a cubic crystalline structure, analogous to diamond.
Early tests indicate that Q-BN is harder than diamond, and
it holds an advantage over diamond when it comes to creating cutting tools.
Diamond, like all carbon, reacts with iron and ferrous materials. Q-BN does
not. The Q-BN has an amorphous structure, and it can easily be used to coat
cutting tools, preventing them from reacting with ferrous materials.