In the last ten years, diamond nanopowders have aroused considerable interest among those engaged in both fundamental and applied investigations. An efficient commercial technology of synthesis of diamond crystals in nanometric range by detonation of oxygen-deficient explosives has been developed in Ukraine. A combination of properties inherent in the diamond nature and a specific surface structure of the particles, which is inherent in cluster materials imparts new quality characteristics to the above material.

In the present paper we have described properties and characteristics of the UDD detonation-synthesized nanopowders (produced by the ALIT company, Ukraine) and of the UDAP polycrystalline micron powders produced by high pressure-high temperature sintering followed by crushing of the resulting compacts.

X-ray studies have shown that the diamond nanopowder is a single-phase material, whose crystal lattice is of a cubic system (a = 3.57 Å), the CSA size (subgrains) is 4 nm, the dislocation density is 1.8.1013 cm-2, and microstresses are absent. The pycnometric density of the nanodiamond is 3.2 g/cm3 and the specific surface of particles is about 200 m2/g. The particle surface contains a great number of uncompensated bonds, because of which the particles are prone to adsorption and agglomeration.

Using the low-temperature nitrogen adsorption (the BET method) and IR spectroscopy, we have ascertained that the diamond particles have a hypomolecular structure of a variable activity, which depends on the nature and amount of functional groups (mainly carbonyl, carboxyl and hydroxyl) adsorbed during the powder synthesis and chemical purification. The –OH groups exerts the strongest effect on the variation of the particle surface activity.

The pycnometric density of particles of the UDDP micropowders is about 3g/cm3. Raman spectroscopy and transmission electron microscopy of the powders have allowed us to reveal the presence of carbon onions in the UDD diamond and practically total absence of them in the UDDP micropowders.

The results of the use of the above diamond powders for precision polishing of elements of laser, optics, electronics, etc. are also given.