title: Topochemistry of Bowtie- and Star-Shaped Metal Dichalcogenide Nanoisland Formation.
abstract: A large number of experimental studies over the past few years observed the formation of unusual highly symmetric polycrystalline twinned nanoislands of transition metal dichalcogenides, resembling bowties or stars. Here, we analyze their morphology in terms of equilibrium and growth shapes. We propose a mechanism for these complex shapes' formation via collision of concurrently growing islands and validate the theory with phase-field simulations that demonstrate how highly symmetric structures can actually emerge from arbitrary starting conditions. Finally, we use first-principles calculations to propose an explanation of the predominance of high-symmetry polycrystals with 60° lattice misorientation angles.
authors.affiliation: Department of Materials Science and NanoEngineering, Rice University , Houston, Texas 77005, United States.
authors.forename: Vasilii I
authors.initials: VI
authors.lastname: Artyukhov
authors.affiliation: Department of Materials Science and NanoEngineering, Rice University , Houston, Texas 77005, United States.
authors.forename: Zhili
authors.initials: Z
authors.lastname: Hu
authors.affiliation: Department of Materials Science and NanoEngineering, Rice University , Houston, Texas 77005, United States.
authors.forename: Zhuhua
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Materials Science and NanoEngineering, Rice University , Houston, Texas 77005, United States.
authors.forename: Boris I
authors.initials: BI
authors.lastname: Yakobson
keywords: 2D materials; Wulff construction; chemical vapor deposition; grain boundaries; synthesis; transition metal dichalcogenides