Spherical nanometer-sized diamond obtained from detonation

Ultrafine diamond (UFD) was synthesized under high pressure and high temper atures generated by explosive detonation. The structure, composition, surfa ce and thermal stability of UFD were studied by use of XRD, TEM, Raman Spec troscopy, FTIR, etc. The influences of the synthesis conditions and purific ation conditions on the properties of UFD were analyzed. The UFD had an ave rage size of 4-6 nm, commonly exhibiting a spherical shape. The highest yie ld was of up to 10 mass% of the explosive. Attempts were made to use UFD as an additive to metal-diamond sintering and as crystallite seeds of CVD dia mond films. The results show that UFD can decrease the coefficient of frict ion of the composite by 30%, and raise the nucleation density in CVD diamon d films by 2-3 times. (C) 2000 Elsevier Science S.A. All rights reserved.