Stabilizing the metastable superhard material wurtzite boron nitride by three-dimensional networks of planar defects

Research Highlight

Superhard material promises next-generation electronics

© Cavan Images/Getty

© Cavan Images/Getty

Millimetre-sized crystals of the superhard semiconductor wurtzite boron nitride (w-BN) can now be fabricated at atmospheric pressure and moderate temperatures.

As hard as a diamond and having a wide electronic band gap and high thermal conductivity, w-BN is a metastable form of BN that is attracting considerable attention for potential use in next-generation electronics.

Current methods for producing w-BN involve direct conversion of hexagonal BN (h-BN) at high pressures. However, the bulk of the material returns to its h-BN form when the pressure is released, leaving only small amounts of w-BN crystals with micrometre-sized grains.

By introducing planar defects into the crystals, a team of scientists led by researchers from the Advanced Institute for Materials Research at Tohoku University was able to delay the transformation from w-BN to h-BN and produce millimetre-sized crystals of w-BN.

Supported content

  1. PNAS 116, 11181–11186 (2019). doi: 10.1073/pnas.1902820116
Institutions Share
Shenyang National Laboratory for Materials Science (SYNL), IMR CAS, China 0.31
Research Center for Functional Materials (RCFM), NIMS, Japan 0.25
Tohoku University, Japan 0.17
Japan Fine Ceramics Center (JFCC), Japan 0.17
Chongqing University (CQU), China 0.06
The University of Tokyo (UTokyo), Japan 0.04