A molecular dynamics study of structural relaxation in tetrahedrally coordinated nanocrystals.
The reorganisation of nanocrystals in order to reduce their surface energies has been examined in computer simulations. The relaxation takes a qualitatively different path for sphalerite- and wurtzite-structured particles. The surfaces of the sphalerite particles reconstruct into hexagonal nets, but the interior remains identifiable as sphalerite-like, whereas wurtzite particles form facetted, hexagonal nanorods by virtue of a reorganisation of the whole particle which involves the creation of a low energy internal interface between oppositely oriented domains. Despite the reorganisation, the diffraction patterns remain compatible with a wurtzite structure with some internal strain. The dipole moments of thermalized wurtzite particles are compared with experimental results for CdSe.
Morgan
Benjamin J
BJ
School of Chemistry, Trinity College, University of Dublin, Dublin 2, Ireland. morganb@tcd.ie
Madden
Paul A
PA
D019187:Cadmium Compounds / Q000737:chemistry*; D003198:Computer Simulation; D003460:Crystallization; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D044367:Phase Transition; D013440:Sulfides / Q000737:chemistry*; D013499:Surface Properties; D017967:Zinc Compounds / Q000737:chemistry*
D019187:Cadmium Compounds; D013440:Sulfides; D017967:Zinc Compounds; C031238:zinc sulfide