Spectroscopic methods of investigation and the thermal stability of detonation nanodiamonds

The behavior of detonation nano- and microdiamonds at increased temperatures is studied by synchronous thermal analysis, X-ray diffraction analysis, and scanning electron microscopy. The X-ray analysis of survived samples shows that a part of the nanodiamond is stable under heating to 1500°C. At the heating to 600°C, we see the decreasing of nanodiamond phase. Appearance of graphite phase isn't observed in the sample up to 1500°C. However, in the range Bragg angle 20-32° after heating to 1500°C, the x-ray amorphous graphite-like phase is observed. The analysis of microphotographs of samples before and after heating showed the influence of heating rate on the parameters of powder particles. A high thermal stability of detonation microdiamonds (above 1500°C) is established. Literature data on the radiation stability of diamond are analyzed. It is established that the character of the diamond damage depends on the type and dose of the irradiation. (paper)