An in-situ observation of amorphization of carbyne particle under electron-beam irradiation

摘要

The family of carbynes with a hexagonal structure is known as linear allotropic modifications of carbon with sp-hybridization of the atomic orbitals. Some investigators reported that both oriented films or single-crystals of carbyne are easily subject to electron-beam radiation damage when the carbynes are irradiated by an electron beam parallel to the hexagonal c-axis. The reaction is assumed to proceed due to a cracking of the conjugated triple-bonded or cumulated double-bonded carbon chains. However, rapid destruction of carbyne crystals by electron irradiation does not permit application of a HREM technique. Therefore, the detailed cracking process has not yet been clarified. In order to investigate the above cracking process, the specimen should be a single-crystal without crystal defects. Single-crystal particles of films of carbyne have been prepared by the following methods: (1) condensation of carbon vapour produced by an electrical arc; (2) chemical carbonization of a poly(vinylidene) film; (3) ion sputtering of graphite; (4) shock-loading of a glass carbon/Cu powder mixture.