Paper 2002-08

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<b Microstructure and spectroscopy studies on cubic boron nitride synthesized under high-pressure conditions

Journal of Physics-Condensed Matter 14 (44): 10983-10988 Nov 11 2002

¹Nistor LC, ¹Nistor SV, ²Dinca G, ²Georgeoni P, ³Van Landuyt J, ⁴Manfredotti C, ⁴Vittone E

¹Natl Inst Mat Phys, Bucharest, Romania and Natl Inst Mat Phys, Bucharest, Romania ²Dacia Synthet Diamonds Factory, Bucharest, Romania ³Univ Antwerp, RUCA, EMAT, B-2020 Antwerp, Belgium ⁴Univ Turin, Expt Phys Dept, I-10126 Turin, Italy

Keywords: POINT-DEFECTS, CRYSTALS, DIAMOND

Abstract

High-resolution electron microscopy (HREM) studies of the microstructure and specific defects in hexagonal boron nitride (h-BN) precursors and cubic boron nitride (c-BN) crystals made under high-pressure high-temperature conditions revealed the presence of half-nanotubes at the edges of the h-BN particles. Their sp(3) bonding tendency could strongly influence the nucleation rates of c-BN. The atomic resolution at extended dislocations was insufficient to allow us to determine the stacking fault energy in the c-BN crystals. Its mean value of 191 +/- 15 mJ m(-2) is of the same order of magnitude as that of diamond. High-frequency (94 GHz) electron paramagnetic resonance studies on c-BN single crystals have produced new data on the D1 centres associated with the boron species. Ion-beam-induced luminescence measurements have indicated that c-BN is a very interesting luminescent material, which is characterized by four luminescence bands and exhibits a better resistance to ionizing radiation than CVD diamond.