title: Low-temperature orientationally ordered structures of two-dimensional C60.
abstract: Orientationally ordered structures of two-dimensional (2D) C(60) at low temperature have been investigated theoretically and experimentally. Using total energy optimization with a phenomenological potential, we find the ground state is a close packed hexagonal lattice in which all the molecules have the same orientation. Several local minima of the potential energy surface are found to be associated with other 1 x 1 lattices as well as 2 x 2 lattices. The energies of the orientational domain boundaries of the 1x1 lattices are also computed, and two kinds of which yield negative values. A majority of these theoretical findings are confirmed by our low-temperature scanning tunneling microscopy study of a 2D C(60) array supported on a self-assembled monolayer.
authors.affiliation: Open Laboratory of Bond Selective Chemistry and Structure Research Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: Lan-Feng
authors.initials: LF
authors.lastname: Yuan
authors.forename: Jinlong
authors.initials: J
authors.lastname: Yang
authors.forename: Haiqian
authors.initials: H
authors.lastname: Wang
authors.forename: Changgan
authors.initials: C
authors.lastname: Zeng
authors.forename: Qunxiang
authors.initials: Q
authors.lastname: Li
authors.forename: Bing
authors.initials: B
authors.lastname: Wang
authors.forename: J G
authors.initials: JG
authors.lastname: Hou
authors.forename: Qingshi
authors.initials: Q
authors.lastname: Zhu
authors.forename: D M
authors.initials: DM
authors.lastname: Chen