title: Unexpected Huge Dimerization Ratio in One-Dimensional Carbon Atomic Chains.
abstract: Peierls theory predicted atomic distortion in one-dimensional (1D) crystal due to its intrinsic instability in 1930. Free-standing carbon atomic chains created in situ in transmission electron microscope (TEM)1-3 are an ideal example to experimentally observe the dimerization behavior of carbon atomic chain within a finite length. We report here a surprisingly huge distortion found in the free-standing carbon atomic chains at 773 K, which is 10 times larger than the value expected in the system. Such an abnormally distorted phase only dominates at the elevated temperatures, while two distinct phases, distorted and undistorted, coexist at lower or ambient temperatures. Atom-by-atom spectroscopy indeed shows considerable variations in the carbon 1s spectra at each atomic site but commonly observes a slightly downshifted π* peak, which proves its sp1bonding feature. These results suggest that the simple model, relaxed and straight, is not fully adequate to describe the realistic 1D structure, which is extremely sensitive to perturbations such as external force or boundary conditions.
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba 305-8565, Japan.
authors.forename: Yung-Chang
authors.identifier: 0000-0002-3968-7239
authors.initials: YC
authors.lastname: Lin
authors.affiliation: JEOL Ltd. , 3-1-2 Musashino, Akishima, Tokyo 196-8558, Japan.
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Morishita
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba 305-8565, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Koshino
authors.affiliation: Department of Electrical Engineering, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Chao-Hui
authors.initials: CH
authors.lastname: Yeh
authors.affiliation: Department of Electrical Engineering, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Po-Yuan
authors.initials: PY
authors.lastname: Teng
authors.affiliation: Department of Electrical Engineering, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Po-Wen
authors.initials: PW
authors.lastname: Chiu
authors.affiliation: JEOL Ltd. , 3-1-2 Musashino, Akishima, Tokyo 196-8558, Japan.
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Sawada
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba 305-8565, Japan.|Department of Mechanical Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
authors.forename: Kazutomo
authors.initials: K
authors.lastname: Suenaga
keywords: EELS; Graphene; Peierls distortion; STEM; carbon atomic chain; carbon dimerizing