Defects and impurities in nanodiamonds: EPR, NMR and TEM study

Solid state magnetic resonance investigation of the thermally-induced structural evolution of silicon oxide-doped hydrogenated amorphous carbon

“…Any structural picture must take account of sp 2 carbon bond defects [9,33,45,46]. Some amount of paramagnetic contribution from -bond graphitic networks might also be present, considering the carbon sp 2 content of these films (Fig.…”

“…This lack of knowledge inhibits developing a fundamental understanding of the mechanisms by which the excellent thermal stability and tribological performance of a-C:H:Si:O are achieved. To gain insights into the structure and composition of DLCs, some of the most powerful tools in the material characterization arsenal have been used, including Raman spectroscopy [9,[16][17][18][19], X-ray photoelectron spectroscopy (XPS) [13,20,21], near edge X-ray absorption fine structure (NEXAFS) spectroscopy [22][23][24], electron energy loss spectroscopy (EELS) [25], Fourier-transform infrared spectroscopy (FT-IR) [26], X-ray reflectivity (XRR) [25], forward recoil elastic scattering (FRES) [27], nuclear magnetic resonance (NMR) spectroscopy [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41], and electron paramagnetic resonance (EPR) spectroscopy [42][43][44][45][46].…”

Size Modification of Nanographite System of Activated Carbon Fibers Studied by EPR

“…Pristine ACFs are characterized by single Lorentzian line recorded below 100 K at g = 2.0031 -value characteristic of carbon materials: graphite g ⊥ = 2.0031 [7], nanodiamond g = 2.0029 [8], and C 60 fullerene g = 2.0026 [9]. When guest molecules are adsorbed in ACFs' voids, EPR spectrum becomes modified -a broader component of EPR signal appears for all studied systems -EPR signal of filled ACFs consists of three lines.…”

“…Observed changes of line width, together with a small g-shift from g e -spectroscopic splitting factor of free electron (g − g e = ∆g = 6 × 10 −4 ; mean value) for line (2) of C 6 H 5 NO 2 -filled ACFs, enabled us to estimate the size of graphite nanoparticles (approximately 1.34 nm) in which distance between graphene plates could be modified by guests molecules [11]. Such an approach was also proposed for ultra dispersed diamond (UDD) [8] and fullerenes [12]. Line width and g-factor of the component (3) of observed EPR spectrum strongly depend on temperature -it can be explained as a surface effect of ACFs.…”

Composite Coatings of Chromium and Nanodiamond Particles on Steel

“…Detonation nanodiamonds from different producers may differ significantly in their properties. This concerns also their crystal structure and outer shell [11][12][13].…”