The consolidation process and microstructure analysis of synthesized diamonds within fractal nature analysis

Abstract

The development of new technologies is very often based on improvement of novel materials and the features of the existing ones as well as their application. Considering that the synthetic diamonds are one of the most appealing areas of modern materials science and its modern applications, the research in this area is becoming more intensive. Therefore, in this paper, an overview of the basic properties of natural and synthesized diamonds is firstly presented followed by the method of forming and parameters that affect the final properties of polycrystalline diamonds. The first method which was used for obtaining synthesized diamonds was HPHT (high pressure high temperature) method, by which were produced diamonds very similar to the natural ones. However, CVD (chemical vapor deposition) method for obtaining polycrystalline diamond films was more promising. By applying this method microcrystalline diamond (MCD) with grain size larger than 100 nm were created. Considering that there were some disadvantages of MCD, new nanocrystalline (NCD) and ultra-nanocrystalline (UNCD) diamond materials were developed, which average size of grains were 5-100 nm as well as 3-5 nm. Depending on the consolidation process (composition and pressure of applied gases, filament setup and reactor geometry) the properties of polycrystalline diamonds can vary. Detailed analysis of these materials nature can be additionally obtained by application of the fractal analysis which is presented in this paper.