title: A hierarchical lattice structure and formation mechanism of ZnO nano-tetrapods.
abstract: The existence of characteristic longitudinal optical and transverse optical phonons of cubic ZnO in ZnO nano-tetrapods is determined by Raman spectroscopy and first-principles calculations. Stacking sequence change at the boundary of the core and legs is also identified by high-resolution transmission electron microscopy. Based on this experimental and theoretical evidence, we demonstrate that the lattice structure of ZnO nano-tetrapods is hierarchical with a zinc blende core connecting to four wurtzite legs. Furthermore, we establish the atomic configuration and propose a formation mechanism induced by Laplace pressure in the initial growth stage of ZnO nano-tetrapods.
authors.affiliation: Fujian Key Laboratory of Semiconductor Materials and Applications, Department of Physics, Xiamen University, Xiamen 361005, People's Republic of China.
authors.forename: Yaping
authors.initials: Y
authors.lastname: Wu
authors.forename: Xian-Hua
authors.initials: XH
authors.lastname: Zhang
authors.forename: Fuchun
authors.initials: F
authors.lastname: Xu
authors.forename: Lan-Sun
authors.initials: LS
authors.lastname: Zheng
authors.forename: Junyong
authors.initials: J
authors.lastname: Kang