title: From sphere to multipod: thermally induced transitions of CdSe nanocrystals studied by molecular dynamics simulations.
abstract: Molecular dynamics (MD) simulations are used to show that a spherical zinc blende (ZB) nanocrystal (NC) can transform into a tetrapod or an octapod as a result of heating, by a local zincblende-to-wurtzite phase transformation taking place in the NC. The partial sphere-to-tetrapod or sphere-to-octapod transition occurs within simulation times of 30 ns and depends on both temperature and NC size. Surprisingly, the wurtzite (WZ) subdomains are not formed through a slip mechanism but are mediated by the formation of highly mobile Cd vacancies on the ZB{111} Cd atomic planes. The total potential energy of a tetrapod is found to be lower than that of a ZB sphere at the same numbers of atoms. The simulation results are in good agreement with experimental high-resolution transmission electron microscopy (HR-TEM) data obtained on heated colloidal CdSe NCs.
authors.affiliation: Process and Energy Laboratory, Delft University of Technology, Leeghwaterstraat 44, 2628 CA Delft, The Netherlands.
authors.forename: Zhaochuan
authors.initials: Z
authors.lastname: Fan
authors.forename: Anil O
authors.initials: AO
authors.lastname: Yalcin
authors.forename: Frans D
authors.initials: FD
authors.lastname: Tichelaar
authors.forename: Henny W
authors.initials: HW
authors.lastname: Zandbergen
authors.forename: Elise
authors.initials: E
authors.lastname: Talgorn
authors.forename: Arjan J
authors.initials: AJ
authors.lastname: Houtepen
authors.forename: Thijs J H
authors.initials: TJ
authors.lastname: Vlugt
authors.forename: Marijn A
authors.initials: MA
authors.lastname: van Huis