Thermal oxidation of detonation nanodiamond

In this work the results of investigation of detonation ultradispersed diamond (UDD) powder by means of thermogravimetric analysis (TGA) and Raman scattering (RS) are presented. Using the TGA method the temperature regions corresponding to the oxidation of different carbon fractions included in the composition of UDD powder were determined. In particular, it was established that heat treatment in the air at a temperature not exceeding 550°C leads to the oxidation and removal of nondiamond carbon, while the diamond part of the UDD remains unchanged. The form of the diamond RS band in the spectra of the UDD powder oxidized at 550°C shows good agreement with the model of phonon confinement. Based on the comparison of the results of experimental data and theoretical calculations for the RS band forms the size of the UDD crystal grains was defined as 4–5 nm.