Towards novel tools for in operando TEM: Plasma modification live

拟议的项目侧重于开发先进的方法，以阐明在等离子体相互作用过程中(例如，在等离子体界面)固体的结构和化学修饰，并使用电子显微镜技术。对经过外部低压等离子体修饰的纳米结构和网络结构的非原位表征作为基础实验，以便通过在透射电子显微镜内的大气微放电来建立具有高度挑战性的原位和手术检查。为此，将设计一种用于在瞬变电磁法中实现的微型等离子体池。等离子体表面修饰和纳米结构生长的目标材料从陶瓷薄膜(Ni3N、Fe3N)到(杂化)的氧化锌和二氧化锡网络、航空石墨、氮化硼和氮化镓等新型多孔网络结构。样品的制备必须适应实验的特殊需要，例如包括在透射电子显微镜内进行原位结晶。微观结构观察包括最先进的传输技术以及表面敏感电子显微镜，使其能够监测等离子体处理后等离子体界面上最初发生的修改。用于原位和手术实验的微型等离子体池将被设计来了解等离子体参数(粒子和能量通量)对等离子体界面过程的影响。该项目将分别协作地结合了从事等离子体处理和微等离子体以及透射电子显微镜，特别是原位技术和化学分析的原理研究人员的知识。该项目的最终目标是研究在Operando中等离子体界面的结构演变，如特征缺陷的形成、表面重建和纳米结构的生长。严重的等离子体改性也将通过最先进的X射线衍射进行监测，从而在更大的长度范围内提供补充信息。

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.