Highly efficient energy conversion and storage technologies such as high‐temperature solid oxide fuel and electrolysis cells, all‐solid‐state batteries, gas separation membranes, and thermal barrier coatings for advanced turbine systems depend on advanced materials. In all cases, processing of ceramics and metals starting from powders plays a key role and is often a challenging task. Depending on their composition, such powder materials often require high sintering temperatures and show an inherent risk of abnormal grain growth, evaporation, chemical reaction, or decomposition, especially in the case of long dwelling times. Electric current‐assisted sintering (ECAS) techniques are promising to overcome these restrictions, but a lot of fundamental and practical challenges must be solved properly to take full advantage of these techniques. A broad and long‐term expertise in the field of ECAS techniques and comprehensive facilities including conventional field‐assisted sintering technology/spark plasma sintering (FAST/SPS), hybrid FAST/SPS (with additional heater), sinter forging, and flash sintering (FS) devices are available at the Institute of Energy and Climate Research: Materials Synthesis and Processing (IEK‐1). Herein, main advantages and challenges of these techniques are discussed and the concept to overcome current limitations is introduced on selected examples.

Accepted Article This article is protected by copyright. All rights reserved Even though advanced ceramics are widely applied as consumables in semiconductor etching processes, the erosion mechanisms and connected surface phenomena are not fully understood. Through the interaction with reactive species and ion bombardment during the plasma exposure, oxide ceramic materials like Y 2 O 3 are eroded by a physico-chemical mechanism. In this paper, fundamental phenomena of surface-plasma interactions were investigated directly at the surface as well as in the near-surface region after exposure to fluorine-based etching plasmas. A straightforward re-localization technique was used to investigate the microstructural features before and after the plasma exposure for up to 2 h. Electron microscopy methods (SEM, EBSD) were coupled with atomic force microscopy (AFM), secondary ion mass spectroscopy (SIMS), and transmission electron microscopy (TEM) to study the surface topography and the corresponding reaction layer. Direct correlation of the microstructure before plasma exposure with the surface topography reveals a novel orientation-dependent erosion mechanism that forms plateau-like structures. Furthermore, the indepth analysis of the near-surface area highlights the influence of the applied bias voltage on the physical damage and chemical gradient formation due to plasma exposure. The combined investigation of surface morphology and near-surface properties reveals new fundamental aspects of the erosion behavior of polycrystalline yttria in CF 4-based etching plasmas.

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