Diamond is the hardest and most widely used of the hard and superhard materials, which together represent an annual market in the multibillions of pounds.
In 1989, a C3N4 carbon nitride with a greater hardness than diamond was predicted theoretically and has now, at last, been experimentally synthesised.
Application
Development Status
Engaging with suppliers to develop scale-up
IP Status
Priority patent application was filed
Opportunity
There has long been a gap in the superhard materials market for a solid which could match the hardness of diamond (~90 GPa) but also improve on some of the issues encountered with the use of diamond, such as its large indirect bandgap and chemical reactivity with iron.
The next hardest material, cubic boron nitride (c-BN, hardness ~60 GPa), while not suffering from the same issues, is significantly softer than diamond. This novel carbon nitride solves these problems, with a predicted hardness between 77 and 87GPa, no chemical reactivity with iron and a smaller bandgap.
Technology
This novel carbon nitride, oP28-C3N4, has been recovered to ambient pressure and temperature and demonstrated a bulk modulus above 300 GPa, making it ultra-incompressible. While the hardness has not yet been measured experimentally, theoretical predictions, as well as the combination of its experimentally measured crystal structure and bulk modulus, strongly suggest that oP28-C3N4 will also be superhard, within 10% of the hardness of diamond. It is composed of corner-sharing CN4 tetrahedra and has been shown to be stable in air over a timescale of months.
Benefits
Quote TEC1104551
