title: Electron beam-assisted healing of nanopores in magnesium alloys.
abstract: Nanopore-based sensing has emerged as a promising candidate for affordable and powerful DNA sequencing technologies. Herein, we demonstrate that nanopores can be successfully fabricated in Mg alloys via focused electron beam (e-beam) technology. Employing in situ high-resolution transmission electron microscopy techniques, we obtained unambiguous evidence that layer-by-layer growth of atomic planes at the nanopore periphery occurs when the e-beam is spread out, leading to the shrinkage and eventual disappearance of nanopores. The proposed healing process was attributed to the e-beam-induced anisotropic diffusion of Mg atoms in the vicinity of nanopore edges. A plausible diffusion mechanism that describes the observed phenomena is discussed. Our results constitute the first experimental investigation of nanopores in Mg alloys. Direct evidence of the healing process has advanced our fundamental understanding of surface science, which is of great practical importance for many technological applications, including thin film deposition and surface nanopatterning.
authors.affiliation: School of Physics and Technology, Center for Electron Microscopy and MOE Key Laboratory of Artificial Micro- and Nano-structures, Wuhan University, Wuhan 430072, China.
authors.forename: He
authors.initials: H
authors.lastname: Zheng
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu
authors.forename: Fan
authors.initials: F
authors.lastname: Cao
authors.forename: Shujing
authors.initials: S
authors.lastname: Wu
authors.forename: Shuangfeng
authors.initials: S
authors.lastname: Jia
authors.forename: Ajing
authors.initials: A
authors.lastname: Cao
authors.forename: Dongshan
authors.initials: D
authors.lastname: Zhao
authors.forename: Jianbo
authors.initials: J
authors.lastname: Wang