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“Microstructure and spectroscopy studies on cubic boron nitride synthesized under high-pressure conditions”. Nistor LC, Nistor SV, Dinca G, Georgeoni P, van Landuyt J, Manfredotti C, Vittone E, Journal of physics : condensed matter 14, 10983 (2002). http://doi.org/10.1088/0953-8984/14/44/414
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.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.649
Times cited: 7
DOI: 10.1088/0953-8984/14/44/414
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“The influence of the h-BN morphology and structure on the c-BN growth”. Nistor L, Teodorescu V, Ghica C, van Landuyt J, Dinca G, Georgeoni P, Diamond and related materials
T2 –, 11th European Conference on Diamond, Diamond-like Materials, Carbon, Nanotubes, Nitrides and Silicon Carbide (Diamond 2000), SEP 03-08, 2000, OPORTO, PORTUGAL 10, 1352 (2001). http://doi.org/10.1016/S0925-9635(00)00377-0
Abstract: The morphology and structure of hexagonal graphitic BN (h-BN) powders with graphitization indices GI <5, used as precursors for the synthesis of cubic BN (c-BN) crystals, has been investigated by transmission electron microscopy in diffraction contrast and high resolution. We show that besides the GI, which is a general parameter for controlling the structural quality of h-EN ponders, some other microstructural features strongly influence the synthesis of c-BN. In our opinion, the high reactivity of some h-BN powders results from the presence of some nucleation centers for c-BN, observed at the edges of the h-BN particles. They are formed by a rearrangement of the graphitic (0002) planes by bending back, joining in pairs and forming locally nanoarches (half nanotubes). In these particular places, the nature of bonding locally turns towards sp(3), as in the case of c-BN, (C) 2001 Elsevier Science B.V. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.561
Times cited: 17
DOI: 10.1016/S0925-9635(00)00377-0
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“High resolution electron microscopy and electron spin resonance studies on cubic boron nitride crystals made by high-pressure/high-temperature synthesis”. Nistor L, Nistor SV, Dincã, G, van Landuyt J, Schoemaker D, Copaciu V, Georgeoni P, Arnici N, Diamonds an related materials 8, 738 (1999). http://doi.org/10.1016/S0925-9635(98)00282-9
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.561
Times cited: 7
DOI: 10.1016/S0925-9635(98)00282-9
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