Aberration-corrected microscopy and spectroscopy analysis of pristine, nitrogen containing detonation nanodiamond (Phys. Status Solidi A 10/2013)
Stuart Turner, Olga Shenderova, Fabiana Da Pieve, Ying-gang Lu, Emrah Yücelen, Jo Verbeeck, Dirk Lamoen and Gustaaf Van Tendeloo
Version of Record online: 18 OCT 2013 | DOI: 10.1002/pssa.201370062
Aberration-corrected transmission electron microscopy (TEM), electron energy-loss spectroscopy (EELS), and density functional theory (DFT) calculations are used by Turner et al. (pp. 1976–1984) to solve several key questions about the surface structure, the particle morphology, and the distribution and nature of nitrogen impurities in detonation nanodiamond. High-resolution TEM demonstrates the stability of ultrasmall nanodiamonds under electron illumination at low acceleration voltage and is used to image the surface structure of detonation nanodiamond. Highresolution EELS measurements on the fine structure of the carbon K-edge demonstrate that the typical π* pre-peak of nanodiamond in fact consists of three sub-peaks that arise from the presence of minimal fullerene-like reconstructions at the nanoparticle surfaces and deviations from perfect sp3 coordination at defects. Spatially resolved EELS experiments evidence the presence of nitrogen within the core of detonation nanodiamond particles. The nitrogen is present throughout the whole diamond core, and can be enriched at defect regions. By comparing the fine structure of the experimental nitrogen K-edge with calculated ELNES spectra from DFT, the embedded nitrogen is most likely related to single substitutional and/or A-center nitrogen, combined with larger nitrogen clusters.