Investigation of Microdiamonds Obtained by the Oxygen-Acetylene Torch Method

The results of experiments on the synthesis of micro- and nano-diamonds by an oxy-acetylene torch on the surface of the pre-deposited copper thin films are presented in this article. The influence of thickness of a buffer copper film and the ratio of the concentrations of oxygen and acetylene on the structure of the deposited samples has been studied in the course of the conducted experiments. The studies by Raman scattering and scanning electron microscopy showed that the synthesis of micro- and nano-diamonds occurs under certain experimental conditions. From the results of the analysis of the obtained samples by the methods of Raman scattering and scanning electron microscopy, it was determined that the deposition time of the copper films and consequently its thickness mainly influence on the structure formation of diamond crystals. On copper films grown for 30 min, the Raman scattering method showed a shift of the diamond peak from the standard (1332 cm‒1) to the low-frequency band (1331.3 cm‒1), which may occur after the presence of stress in the crystals. The results of the investigation showed that with increasing of synthesis time take place smoothing of the facets of crystallites (scanning electron microscopy) and decrease in intensity of the diamond peaks (Raman scattering method). В