Babaev V.G., Guseva M.B., Novikov N.D., Savchenko N.F., Khvostov V.V.
The paper deals with the effect of a shock wave generated by a laser pulse on two carbon materials, namely, pyrolytic graphite and a 10-mcm film of amorphous linear-chain carbon. The samples are irradiated by a neodymium laser with the wavelength of 1.06 µm in a vacuum of 0.3 Pa, recovered, and then investigated by the methods of transmission electron microscopy (TEM) and Auger spectroscopy. The laser pulse energy is approximately 70 J, with the duration of 580 ps and intensity of 440 GV/cm2. In the recovered samples, the formation of crystalline carbyne is observed with the lattice parameter a of 0.516 and 0.533 nm. Closely packed carbine crystals are revealed for the first time, which consist of linear chains without kink, as well as crystals of the characteristic size of -10 µm, which is an order of magnitude larger than the previously observed sizes. The electron diffraction data are used to calculate the electron potentials of carbyne crystals. The calculation results confirm that the carbon chains are packed in a close-packed hexagonal structure with minor distinctions for crystals formed in different parts of the sample. A minor amount of ultradisperse diamond is further detected in recovered samples of amorphous carbon.