FT1 Early stages of phase transitions
Prof. Dirk Zahn
Computer Chemistry Center
Cluster of Excellence
Engineering of Advanced Materials
The early stages of materials formation, that is, the association of dispersed constituents and their structural organization into particles (nucleation events) that lead to the transformation of one phase to another, constitutes a major challenge to both scientific endeavor and practical engineering. The synthesis of nanocrystalline matter includes ‘bottom-up’ approaches which make use of atomic/molecular self-organization to fabricate novel species of materials. Thus, by focusing on the underlying mechanisms of nucleation and growth with joint efforts from experiment and theory, we wish to optimize synthetic routes and discover new materials from rational design.
Synthesis & experimental characterization
It is the main goal of the experimental studies to prepare the ground for a fundamental understanding of nucleation and growth of a few carefully selected exemplary systems. For that purpose well established methods like small angle X-ray neutron scattering (SAXS, SANS) and spectroscopic (Raman, IR, EXAFS, UV-VIS) techniques will be utilized. It is obviously a major challenge to optimize the methods to achieve high spatial and temporal resolution in order to resolve the particle formation process on an atomic level.
Modeling & Simulation
New approaches to molecular simulation have paved the way to realistic crystal nucleation scenarios with direct relation to solid state chemistry and materials science. Starting from the association of single ions in solvent environments, available insights range from the mechanisms of motif formation, ripening reactions and the self-organization of nanocrystals to interactions with growth-controlling additives. The latter issue yields a new perspective toward understanding the structure of functionalized nanocrystals and the precipitation of composite materials. By understanding and then rationally manipulating the molecular processes of self-organization that govern both, structure and shape, we shall strengthen the bottom-to-top approach for the development of smart nanomaterials.