Abstract

Three types of diamond nanoparticles with sizes from 5 to 1000 nm have been investigated, whose crystal lattices include nitrogen-vacancy (NV) centers: detonation nanodiamonds (DNDs), dynamic-synthesis polycrystalline diamonds, and static-synthesis single-crystal diamonds. The electron paramagnetic resonance spectra have been investigated, along with the luminescence and IR absorption spectra of these materials. The DND concentration of NV⁽⁻⁾ centers is 2.7 ppm and is highest for particles in the size range up to 7 nm. The concentration of NV⁽⁻⁾ centers in polycrystalline diamonds is an order of magnitude less and depends on the average size of the polycrystalline particles, reaching a maximum at 180 nm in the average size range. The luminescence is brightest in 100-nm particles of synthetic Ib diamonds subjected to high-energy-electron irradiation and annealing. The latter with an NV⁽⁻⁾ concentration of around 4 ppm can be used as fluorescent markers at the nanolevel.

© 2018 Optical Society of America