Nanocrystalline diamonds, their properties and applications

Nanodiamond particles with nm dimensions are examined by Raman microspectroscopy and photoluminescence. The structural properties, i.e. the ratio of the graphitic to the diamond phase, can be read from the Raman spectrum and the bands corresponding to the individual structures. The change of the ratio of these bands with the particles' size and their surface passivation shows their surface properties. When doped with a small amount of silicon, the diamond nanoparticles become an effective source of red light when illuminated. This property can be used, for example, in medicine to label specific tissues.