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Author Nistor, L.C.; Nistor, S.V.; Dinca, G.; Georgeoni, P.; van Landuyt, J.; Manfredotti, C.; Vittone, E. pdf  url
doi  openurl
  Title Microstructure and spectroscopy studies on cubic boron nitride synthesized under high-pressure conditions Type A1 Journal article
  Year (down) 2002 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat  
  Volume 14 Issue 44 Pages 10983-10988  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  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.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos 000179541700114 Publication Date 2002-10-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0953-8984; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.649 Times cited 7 Open Access  
  Notes Approved Most recent IF: 2.649; 2002 IF: 1.775  
  Call Number UA @ lucian @ c:irua:103328 Serial 2061  
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Author Nistor, L.; Teodorescu, V.; Ghica, C.; van Landuyt, J.; Dinca, G.; Georgeoni, P. pdf  doi
openurl 
  Title The influence of the h-BN morphology and structure on the c-BN growth Type A1 Journal article
  Year (down) 2001 Publication 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 Abbreviated Journal Diam Relat Mater  
  Volume 10 Issue 3-7 Pages 1352-1356  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  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.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000168730600206 Publication Date 2002-10-14  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0925-9635; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.561 Times cited 17 Open Access  
  Notes Approved Most recent IF: 2.561; 2001 IF: 1.902  
  Call Number UA @ lucian @ c:irua:103421 Serial 3586  
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Author Nistor, L.; Buschmann, V.; Ralchenko, V.; Dinca, G.; Vlasov, I.; van Landuyt, J.; Fuess, H. pdf  doi
openurl 
  Title Microstructural characterization of diamond films deposited on c-BN crystals Type A1 Journal article
  Year (down) 2000 Publication Diamond and related materials T2 – 10th European Conference on Diamond, Diamond-Like Materials, Nitrides, and Silicon Carbide (Diamond 1999), SEP 12-17, 1999, PRAGUE, CZECH REPUBLIC Abbreviated Journal Diam Relat Mater  
  Volume 9 Issue 3-6 Pages 269-273  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract The morphology and structure of diamond films, deposited on cubic boron nitride (c-BN) crystals by microwave-plasma-enhanced chemical vapor deposition, is studied by high-resolution scanning electron microscopy and micro-Raman spectroscopy. The c-BN crystals, with sizes of 200 to 350 mu m and grown by a high-temperature/high-pressure technique, were embedded in a copper holder, and used as substrates in deposition runs of 15 min to 5 h. The nucleation centers for diamond appear as well-shaped cuboctahedral crystallites, having diameters of approximately 100 nm. With increasing deposition time the diamond crystallites grew larger, forming islands on the c-BN faces. In some cases, epitaxial growth was observed on the (111) c-BN faces where coalesced particles gave rise to very smooth regions. A number of diamond crystals with peculiar shapes are observed, such as a pseudo five-fold symmetry due to multiple twinning. Moreover, both randomly distributed carbon tubes, about 100 nn in diameter and 1 mu m in length, and spherically shaped features are observed in samples prepared under the typical conditions of diamond deposition, this effect being ascribed to the influence of plasma-sputtered copper contamination. Quite unusual diamond crystals with a deep, pyramidal-shaped hole in the middle grew on the copper substrate between the c-BN crystals. (C) 2000 Elsevier Science S.A. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000087382400009 Publication Date 2002-07-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0925-9635; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.561 Times cited 9 Open Access  
  Notes Approved Most recent IF: 2.561; 2000 IF: 1.591  
  Call Number UA @ lucian @ c:irua:102877 Serial 2041  
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