Bonding structure of BCN nanopowders prepared by ball millingBonding structure of BCN nanopowders prepared by ball milling
Faculty of Sciences. Physics
Biophysics and Biomedical Physics
Diamond and related materials. - Amsterdam
16(2007):4-7, p. 1450-1454
University of Antwerp
Ternary Boron-Carbon-Nitrogen (BCN) compounds have been prepared as nanometric powders by low-energy ball milling, using as precursors h-BN, graphite and polypropylene micrometric powders. Different proportions of the reactants were used aiming towards the synthesis of BCN, BC2N, BC4N and BCNH2 compositions. Ball milling induces chemical reaction between the precursors resulting in ternary BCN materials in the form of nanoparticles with an average diameter of 60 nm, as revealed by Scanning Electron Microscopy. X-ray Diffraction (XRD) shows a broad peak slightly shifted from the position of main reflection on graphite and h-BN, indicating hexagonal order with lattice distortion and a domain size of about I nm. Infrared spectroscopy confirms the dominant hexagonal bonding structure, although with new spectral features. Additional information on the bonding structure was obtained by X-ray Absorption Near-Edge Spectroscopy (XANES), by comparison with reference samples and amorphous BCN thin films. XANES shows the presence of many pi* peaks, characteristic of sp(2) hybrids forming different types of bonds between the B, C and N atoms, hence proving the atomic mixing within the basal planes. (C) 2007 Elsevier B.V. All rights reserved.