Deciphering the Formation Mechanism of Multiply Twinned Nanostructures by X-ray Scattering

The bend contours of multiply twinned nanoparticles (MTPs) provide an example of how specific crystallographic features dictate the geometric shape of finite-sized crystals. The formation of MTPs during colloidal synthesis can occur through at least two different pathways: A) growth from multiply twinned seeds or B) the stepwise formation of new twin boundaries on single-crystalline seeds (either by particle overgrowth or multiparticle attachment). Despite the abundance of these MTPs in colloidal synthesis, little to none is known about the dynamic transformation from nucleation to crystal growth. This proposal aims to complete a systematic in situ X-ray Scattering of the formation mechanism of MTPs, to understand how the geometry of a crystal shape correlates with the local and global atomic arrangement in presence of twin structures. The influence of reaction temperature and annealing time, surface ligands t on the reaction kinetics will be studied on various nanocrystals.