Synergistic influence of fluorine and hydrogen on processes of thermal transformations of carbon-containing systems under high pressures

Abstract

Thermal transformations of naphthalene (C₁₀H₈), octafluoronaphthalene (C₁₀F₈) and their binary mixtures at 8.0 GPa have been investigated by X-ray diffraction, Raman spectroscopy, scanning and transmission microscopies. As a result, the pronounced synergistic effect of fluorine and hydrogen on mechanisms, p, T parameters and products of pressure-temperature-induced transformations of carbon-containing systems has been established. Simultaneous presence of fluorine and hydrogen gives rise to significant reduction of the temperature thresholds (TT) for carbonization, graphitization and diamond formation in C₁₀H₈ – C₁₀F₈ mixtures in comparison with the TT values for pure C₁₀H₈ and C₁₀F₈ at the same pressure. This synergistic effect manifests itself also in the simultaneous presence in the products of transformation of both nano- and micrometer-sized diamond fractions. The reasons of formation of different diamond fractions in the products of binary mixture treatment are discussed in this work.