Determinants of crystal structure transformation of ionic nanocrystals in cation exchange reactions
Zhanzhao Li, Masaki Saruyama, Toru Asaka, Yasutomi Tatetsu, Toshiharu Teranishi
Abstract
Shape and nanocrystal transformations Cation exchange reactions that change the composition of a nanocrystal (NC) under mild conditions usually preserve the sublattice of the larger anions. Li et al. found that the shape of roxbyite (Cu 1.8 S) nanocrystals, which have a distorted, hexagonal, close-packed sulfide anion sublattice, affected the outcome of exchange reactions with cobalt ions. Flat nanoplates retained the anion lattice and formed cobalt sulfide, but tall nanorods transformed into Co 9 S 8 nanocrystals with a cubic, close-packed structure. Facile crystal plane sliding in the taller nanocrystals appears to have driven the different layer stacking of sulfide anions. Science , abh2741, this issue p. 332