Post by NCSR "DEMOKRITOS"

This is copper seen at 20,000× magnification. To be more precise, it is copper(II) oxide captured using a Scanning Electron Microscope (SEM) at the Institute of Nanoscience & Nanotechnology at NCSR Demokritos, at 25 kV accelerating voltage. What to most of us seems like a mixture of ice cube structures and tiny spheres, to scientists is a mixture of microstructural features and material indicators (crystal geometry, surface texture, structural irregularities) that can provide clues about its potential and behaviour in real applications, from catalysis to energy storage. And what looks like abstract geometry is actually a material being understood. Unlike Transmission Electron Microscopy (TEM), which can distinguish features inside a material down to the atomic scale, Scanning Electron Microscopy (SEM) maps the surface - scanning it point by point with a focused electron beam. The beam is generated, accelerated to high energies (typically in the kV range), and narrowed into an extremely fine beam using electromagnetic lenses before scanning the sample surface. As the beam scans the surface, it interacts with the material and electrons are emitted or reflected back. How these electrons “bounce back” carries different types of information. Secondary electrons (electrons from the material itself that are knocked out by the incoming beam) capture fine surface details. Backscattered electrons (primary beam electrons that are reflected back out) highlight differences in composition. Additional signals, such as X-rays emitted when the material is hit by the electron beam, enable chemical analysis. By combining these signals, SEM builds a detailed picture of the material’s surface, revealing features that often control performance, from reactivity to durability. Stay tuned to learn more about our labs and our people. #InsideTheLab #SEM #Microscopy #Nanotechnology #ResearchInGreece #NCSRDemokritos #ScienceExplained