Abstract
Recently, a hardness similar to that of diamond has been reported for a quasiternary, nitride-based nanocomposite. The related, quasibinary nanocomposite “,” which may be regarded as the prototype of the family of superhard systems, also exhibits a significant hardness enhancement. Extensive density-functional theory calculations indicate that the superhardness is related to the preferential formation of TiN(111) polar interfaces with a thin -derived layer. The strength of TiN in the direction is similar to that of the weakest bonding direction in diamond. Oxygen impurities cause a significant reduction of the interface strength.
- Received 20 April 2006
DOI:https://doi.org/10.1103/PhysRevLett.97.086102
©2006 American Physical Society