title: Creation of nanostuctures by extreme conditions: high-pressure synthesis of ultrahard nanocrystalline cubic boron nitride.
abstract: The synthesis of high-purity bulk nanostructured cubic boron nitride (cBN) at 20 GPa and 1770 K by direct phase transformation of graphite-like BN with an "ideal random layer" structure is reported. The two-times increase of hardness of nano-cBN (H(V)  = 85 GPa) with respect to conventional polycrystalline cBN (H(V)  ∼ 45 GPa) is evidently a result of nanosize effects.
authors.affiliation: LSPM-CNRS, Université Paris Nord, 99 avenue J.-B. Clément, Villetaneuse, France. vladimir.solozhenko@univ-paris13.fr
authors.forename: Vladimir L
authors.initials: VL
authors.lastname: Solozhenko
authors.forename: Oleksandr O
authors.initials: OO
authors.lastname: Kurakevych
authors.forename: Yann
authors.initials: Y
authors.lastname: Le Godec
mesh_terms: D001896:Boron Compounds / Q000737:chemistry*; D006244:Hardness; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D011312:Pressure; D013696:Temperature
chemical_list: D001896:Boron Compounds; C017282:boron nitride