Towards novel tools for in operando TEM: Plasma modification live

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The proposed project focuses on the development of advanced methods to elucidate the structural and chemical modification of solids during plasma interaction (e.g. at the plasma interface) with in operando electron microscopy techniques. The ex situ characterization of nanostructures and networks modified by an external low-pressure plasma serves as basic experiment in order to establish highly challenging in situ and in operando examinations by an atmospheric micro discharge inside the transmission electron microscope (TEM). For this purpose a miniaturized plasma cell for implementation inside the TEM will be designed. The target materials for surface modification and nanostructure growth at the plasma are ranging from thin ceramic films (Ni3N, Fe3N) up to novel porous network structures like (hybridized) ZnO and SnO2 networks, aerographite, aero-BN and -GaN. The preparation of the samples has to be adapted to the specific needs of the experiments, e.g. including in situ crystallization inside TEM. The microstructural observations include state of the art transmission techniques as well as surface sensitive electron microscopy enabling to monitor the initially occurring modifications at the plasma interface upon plasma treatment. The miniaturized plasma cell applied for the in situ and in operando experiments will be designed to understand the influence of plasma parameters (particle and energy fluxes) on the processes at the plasma interface.This project combines synergistically the knowledge of the principle investigators working on plasma processing and micro plasmas, as well as transmission electron microscopy, especially in situ techniques and chemical analyses, respectively. The ultimate goal of the project is to investigate the structural evolution at the plasma interface in operando, like the formation of characteristic defects, surface reconstruction and nanostructure growth. Severe plasma modification will also be monitored via state of the art X-ray diffraction, thus providing complementary information on larger length scale.