title: Helical growth of aluminum nitride: new insights into its growth habit from nanostructures to single crystals.
abstract: By understanding the growth mechanism of nanomaterials, the morphological features of nanostructures can be rationally controlled, thereby achieving the desired physical properties for specific applications. Herein, the growth habits of aluminum nitride (AlN) nanostructures and single crystals synthesized by an ultrahigh-temperature, catalyst-free, physical vapor transport process were investigated by transmission electron microscopy. The detailed structural characterizations strongly suggested that the growth of AlN nanostructures including AlN nanowires and nanohelixes follow a sequential and periodic rotation in the growth direction, which is independent of the size and shape of the material. Based on these experimental observations, an helical growth mechanism that may originate from the coeffect of the polar-surface and dislocation-driven growth is proposed, which offers a new insight into the related growth kinetics of low-dimensional AlN structures and will enable the rational design and synthesis of novel AlN nanostructures. Further, with the increase of temperature, the growth process of AlN grains followed the helical growth model.
authors.affiliation: Centre for Composite Materials, Harbin Institute of Technology, Harbin 150080, China.
authors.forename: Xing-Hong
authors.initials: XH
authors.lastname: Zhang
authors.affiliation: Institute of Microstructure and Properties of Advanced Materials, Beijing University of Technology, Beijing 100124, China.
authors.forename: Rui-Wen
authors.initials: RW
authors.lastname: Shao
authors.affiliation: Shenzhen Graduate School, Harbin Institute of Technology, Shenzhen 518055, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Jin
authors.affiliation: Nano-Electronics Materials Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan.
authors.forename: Jian-Yu
authors.initials: JY
authors.lastname: Wang
authors.affiliation: 1] Institute of Microstructure and Properties of Advanced Materials, Beijing University of Technology, Beijing 100124, China [2] Materials Engineering and Centre for Microscopy and Microanalysis, The University of Queensland, St. Lucia, Queensland 4072, Australia.
authors.forename: Kun
authors.initials: K
authors.lastname: Zheng
authors.affiliation: Centre for Composite Materials, Harbin Institute of Technology, Harbin 150080, China.
authors.forename: Chao-Liang
authors.initials: CL
authors.lastname: Zhao
authors.affiliation: Centre for Composite Materials, Harbin Institute of Technology, Harbin 150080, China.
authors.forename: Jie-Cai
authors.initials: JC
authors.lastname: Han
authors.affiliation: Nano-Electronics Materials Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan.
authors.forename: Bin
authors.initials: B
authors.lastname: Chen
authors.affiliation: Nano-Electronics Materials Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Sekiguchi
authors.affiliation: Materials Engineering and Centre for Microscopy and Microanalysis, The University of Queensland, St. Lucia, Queensland 4072, Australia.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Materials Engineering and Centre for Microscopy and Microanalysis, The University of Queensland, St. Lucia, Queensland 4072, Australia.
authors.forename: Jin
authors.initials: J
authors.lastname: Zou
authors.affiliation: 1] Centre for Composite Materials, Harbin Institute of Technology, Harbin 150080, China [2] Academy of Fundamental and Interdisciplinary Sciences, Harbin Institute of Technology, Harbin 150080, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Song