Benzene-derived nanothreads

The benzene pressure -- temperature phase diagram has been widely studied. An irreversible phase transformation to an amorphous hydrogenated carbon occurs after compressing benzene to 20 GPa [1-6]. Later synthesis of a crystalline one-dimensional sp3 carbon nanomaterial by a kinetically controlled high-pressure solid-state reaction of benzene was reported [7,8]. These benzene-derived nanothreads may be the first member of a new class of ordered sp3 nanomaterials with unique promise for a diverse range of energy applications [7,8]. We report in-situ Raman and X-ray diffraction characterization of the formation of nanothreads at high pressure. Nanothread formation begins at 14 to 20 GPa, as documented by the appearance of a new diffraction signature. The crystal-to-crystal transformation from solid benzene to nanothreads will be discussed.