Environmental and in-situ scanning electron microscope

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The direction of the Hamburg University of Technology towards becoming a sustainable institution with research excellence has significantly defined the new research structure with five strategic research fields. Several of these fields, e.g. "Advanced Materials & (Bio-) Processes" and "Environmental & Energy Systems" are directly reflected in the currently planned large-scale research projects, the Collaborative Research Center 1615 "Smart Reactors", the Federal Cluster of Excellence "BlueMat: Water-Driven Materials" and the extension of the Research Training Group 2462 "Processes in Natural and Engineered Particle-Fluid Systems". These projects and those described in this proposal rely on the analysis of sample systems in environments with dynamically changing parameters. Key requirements of these projects for sample investigations at the microscopic level include, in addition to humid environments, oxidizing and reducing conditions at temperatures ranging from -20 °C to 1400 °C. To ensure such investigations, an environmental and in-situ scanning electron microscope is required. Especially the possibility to perform temperature- and gas-controlled experiments of electron-transparent samples with a structural resolution of a few nanometers in scanning transmission mode by means of a field emission cathode and a special holder is a necessary condition for the analysis of nanoporous systems, such as aerogels. Also, wetting studies of electron-transparent building material or nanoporous silicon samples are only possible with scanning transmission mode in an environmental and in-situ scanning electron microscope and are not feasible with, for example, in-situ liquid holders for transmission electron microscopes. Additionally, to achieve an improved image quality even under high temperatures and partial pressures, imaging by means of absorbed electron beam current is necessary. A mass spectrometer is intended as an important component for constant monitoring of the gas environment. The Electron Microscopy Unit is the user-based equipment center for electron microscopy at Hamburg University of Technology. The continuous modernization of the Electron Microscopy Unit since 2011 with powerful electron microscopes as well as equipment for sample preparation and tomography was a key prerequisite to enable competitive research, e.g. for the Collaborative Research Center 986. Numerous current and future research projects in materials science, process engineering and building materials technology are based on high-performance electron microscopy in the form of individual or joint projects. With the environmental and in-situ scanning electron microscope applied for here, it will be possible to carry out the planned research projects that rely on the analysis of sample systems in changing environmental conditions.