title: Rotational dynamics of confined C60 from near-infrared Raman studies under high pressure.
abstract: Peapods present a model system for studying the properties of dimensionally constrained crystal structures, whose dynamical properties are very important. We have recently studied the rotational dynamics of C(60) molecules confined inside single walled carbon nanotube (SWNT) by analyzing the intermediate frequency mode lattice vibrations using near-infrared Raman spectroscopy. The rotation of C(60) was tuned to a known state by applying high pressure, at which condition C(60) first forms dimers at low pressure and then forms a single-chain, nonrotating, polymer structure at high pressure. In the latter state the molecules form chains with a 2-fold symmetry. We propose that the C(60) molecules in SWNT exhibit an unusual type of ratcheted rotation due to the interaction between C(60) and SWNT in the "hexagon orientation," and the characteristic vibrations of ratcheted rotation becomes more obvious with decreasing temperature.
authors.affiliation: State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China.
authors.forename: Yonggang
authors.initials: Y
authors.lastname: Zou
authors.forename: Bingbing
authors.initials: B
authors.lastname: Liu
authors.forename: Liancheng
authors.initials: L
authors.lastname: Wang
authors.forename: Dedi
authors.initials: D
authors.lastname: Liu
authors.forename: Shidan
authors.initials: S
authors.lastname: Yu
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
authors.forename: Tianyi
authors.initials: T
authors.lastname: Wang
authors.forename: Mingguang
authors.initials: M
authors.lastname: Yao
authors.forename: Quanjun
authors.initials: Q
authors.lastname: Li
authors.forename: Bo
authors.initials: B
authors.lastname: Zou
authors.forename: Tian
authors.initials: T
authors.lastname: Cui
authors.forename: Guangtian
authors.initials: G
authors.lastname: Zou
authors.forename: Thomas
authors.initials: T
authors.lastname: Wågberg
authors.forename: Bertil
authors.initials: B
authors.lastname: Sundqvist
authors.forename: Ho-Kwang
authors.initials: HK
authors.lastname: Mao