Local structure and paramagnetic properties of the nanostructured carbonaceous material shungite.

Using a scanning electron microscopy, elemental analysis, electron paramagnetic resonance, and Raman scattering methods, two types of the shungite materials (Sh-II from Zazhogino deposit and shungite from a commercial filter (ShF)), with different carbon content and porosity, are studied in this work. It was established by scanning electron microscopy data that the structure of the shungite samples is formed by a micron-size agglomeration of carbon and silicon dioxide clusters. It is found from the Raman data that carbon fraction is formed from sp(2)-hybridized clusters, size of which increases from 9 up to 12 nm after annealing of the samples.