Cyclic Twins of CVD Diamond Crystals

Abstract

Using the example of cyclic twins of CVD diamond, their pseudo-pentagonal and icosahedral forms have been described. It is shown that their general appearance is determined by simple habit forms of crystals (octahedron and cube) in the case of cyclic twinning in accordance with the spinel law on (111) plane. The varieties of cyclic twins are identified. A topographic characteristic of cube and octahedron faces of these complex twins is provided. Models for the formation of pseudo-pentagonal and icosahedral forms of diamond crystals are proposed.