Bor zengini amorf malzemeler

In the scope of this thesis, boron-rich amorphous materials having different boron concentrations (B1-xNx, B1-xOx and B1-xSix) were created as a result of rapid cooling of their liquid state with the help of an ab initio molecular dynamics technique. Their structural, electrical and mechanical properties were exposed in detail. In all boron rich materials, the coordination number of B was found to increase steadily with increasing B content. Similarly N and Si atoms also attained high coordinated motifs with increasing B content. However, the coordination number of O atoms remained null for all compositions. Chemical segregations and hence phase separations were witnessed in most amorphous configurations. The materials with high boron ratios, as expected, consisted of B12 icosahedrons. In addition, the formation of nano-sized B7, B10, B14 and B16 clusters was observed in some boron-rich compounds. Each computer-generated material exhibited a semiconducting character. The mechanical properties (Bulk, Young and Shear moduli) were perceived to increase with increasing B content. Some amorphous compositions were proposed to be hard materials on the basis of their Vickers hardness estimation.