Berlin 2015 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 52: Nanomaterials III: Nanoporous Gold and Phase Transformations

MM 52.4: Vortrag

Donnerstag, 19. März 2015, 12:30–12:45, H 0106

Influence of elastic stresses during the formation of hollow nanoparticles — •Manuel Roussel and Guido Schmitz — Lehrstuhl für Materialphysik, Universität Stuttgart, Heisenbergstr. 3, 70569 Stuttgart, Germany

The formation of hollow particles has been extensively studied during the past few years, and this enthusiasm assuredly comes from the fact that nanometric containers may have several applications in various fields (drug delivery, catalysis, composite materials). A multitude of various hollow architectures have been created, using various methods, as reported in hundreds of publications. However, numerous fundamental questions have not been clarified yet.

This project aims at investigating one of these questions. What mechanisms are involved during the creation of a hollow particle at the atomic scale? More precisely, we try to understand the link between solid state diffusion, non-equilibrium vacancies and diffusion-induced stresses during the formation of a Kirkendall void in core-shell nanostructures.

While finite element simulations allow us to apprehend the problem from a theoretical point of view, we also have a powerful characterization tool at our disposal: the Tomographic Atom Probe (TAP). Here, emphasis will be placed on showing how diffusion and phase transformation can be controlled using stress and geometry in a nanostructure. For instance, we will show how switching from a nanosphere to a nanowire configuration can drastically change diffusion kinetics at the atomic scale.