High-field formation and field ion microscopy of monatomic carbon chains

By methods of field ion microscopy and mass spectrometry, the presence of linear carbon chains at the surface of carbon fibers after high-voltage treatment using a pulse generator with pulse duration of 10 ns was revealed. The carbon chains attached to the specimen tips can be produced in situ in a field ion microscope using low-temperature pulsed evaporation by electric fields of the order of 80 V nm(-1). These nanowires are perfectly resolved in the field ion microscope. An analysis of the cluster images and determination of the field-enhancement factors strongly indicate that the field produced clusters are linear chains of one carbon atom in diameter. The process of field evaporation at the pulse voltage loading is sporadic with an anomalously large instant rate of evaporation corresponding to explosive removal of about 10(11) atomic layers s(-1). Atomic C chains are produced during the high-field unraveling of nanofibers at 4.2 and 77 K.