Magnetic resonance techniques, namely Electron Paramagnetic Resonance (EPR) and solid state Nuclear Magnetic Resonance (NMR), are powerful non-destructive tools for studying electron-nuclear and crystalline structure, inherent electronic and magnetic properties and transformations in carbon-based nanomaterials. EPR allows to control purity of ultradispersed diamond (UDD) samples, to study the origin, location and spin-lattice relaxation of radical-type carbon-inherited paramagnetic centers (RPC) as well as their transformation during the process of temperature driven diamond-to-graphite conversion. Solid state NMR on H-1 and C-13 nuclei provide one with information on the crystalline quality, allows quantitative estimation of the number of different allotropic forms, and reveals electron-nuclear interactions within the UDD samples under study. Results of recent EPR and C-13 NMR study of pure and transition metal doped UDD samples, obtained by detonation technique, are reported and discussed. In addition to characteristic EPR signals, originated form para- and ferromagnetic impurities and doping ions, the UDD samples show a high concentration of RPC (up to 10(20) spin/gram), which are due to structural defects (dangling C-C bonds) on the diamond cluster surface. In-situ EPR sample's vacuumization experiment in conjunction with precise SQUID magnetization measurements allowed concluding that each UDD particle carries a single spin (dangling bond) per each from 8 crystal (I 11) facets bounded the particle.
CITATION STYLE
Shames, A. I., Panich, A. M., Kempiíski, W., Baidakova, M. V., Osipov, V. Yu., Enoki, T., & Vul’, A. Ya. (2005). Magnetic Resonance Study of Nanodiamonds. In Synthesis, Properties and Applications of Ultrananocrystalline Diamond (pp. 271–282). Springer-Verlag. https://doi.org/10.1007/1-4020-3322-2_21
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