title: In situ observation of thermal relaxation of interstitial-vacancy pair defects in a graphite gap.
abstract: Direct observation of individual defects during formation and annihilation in the interlayer gap of double-wall carbon nanotubes (DWNT) is demonstrated by high-resolution transmission electron microscopy. The interlayer defects that bridge two adjacent graphen layers in DWNT are stable for a macroscopic time at the temperature below 450 K. These defects are assigned to a cluster of one or two interstitial-vacancy pairs (I-V pairs) and often disappear just after their formation at higher temperatures due to an instantaneous recombination of the interstitial atom with vacancy. Systematic observations performed at the elevated temperatures find a threshold for the defect annihilation at 450-500 K, which, indeed, corresponds to the known temperature for the Wigner energy release.
authors.affiliation: Research Center for Advanced Carbon Materials, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, 305-8565, Japan.
authors.forename: Koki
authors.initials: K
authors.lastname: Urita
authors.forename: Kazu
authors.initials: K
authors.lastname: Suenaga
authors.forename: Toshiki
authors.initials: T
authors.lastname: Sugai
authors.forename: Hisanori
authors.initials: H
authors.lastname: Shinohara
authors.forename: Sumio
authors.initials: S
authors.lastname: Iijima