Non-traditional carbon semiconductors prepared from fullerite C-60 and carbyne under high pressure

We present the detailed study of X-ray diffraction, Raman and absorption ed ge spectra, mechanical, and transport properties of new metastable carbon p hases prepared from fullerite C-60 and cumulene carbyne by high-pressure-te mperature treatment and also review some recent relevant results. The seque nce of phases obtained gives the picture of temperature-induced. transforma tions under pressure, which are described in terms of covalent bonding of C -60 molecules or cumulene chains in carbyne. Special attention is paid to t he three-dimensional polymerization of fullerite C-60 Experimental data sug gest certain relations between the physical properties of prepared carbon p hases, the majority of which are semiconductors, and the bonding nature of materials, i.e., the number of atoms in differently hybridized carbon state s, structure topology, contribution of van der Waals interaction, etc.