From sphere to multipod: thermally induced transitions of CdSe nanocrystals studied by molecular dynamics simulations.
J Am Chem Soc
; 135(15): 5869-76, 2013 Apr 17.
Article
em En
| MEDLINE
| ID: mdl-23528240
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.
Texto completo:
1
Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article