Unveiling Atomic Surface Structures with Precision at Nagoya University

**Researchers** at **Nagoya University** have pioneered a study using **atomic-resolution secondary electron (SE) imaging** to explore the atomic structures of material surfaces, particularly investigating materials undergoing 'surface reconstruction.' This phenomenon, where surface atoms differ in arrangement from those beneath, had posed challenges in observation at the atomic level. Traditional scanning electron microscopy (SEM) methods were limited due to SEs primarily emitting from shallow depths. Utilizing a two-layered molybdenum disulfide (MoS₂) sample, the researchers distinguished the surface layer by its **higher intensity SE images**, exhibiting a threefold increase compared to the second layer. This discovery signifies SE imaging's heightened sensitivity to surface atomic arrangements. Atomic-resolution images revealed **stunning honeycomb structures** and overlapping patterns, providing unique insights into atomic arrangements. Koh Saitoh from Nagoya University's Institute of Materials and Systems for Sustainability (IMaSS) explains that the surface layer's absorption of SEs contributes to the technique's depth sensitivity. Understanding these differences is critical for the **control of nanomaterials' growth, fabrication, and properties**, particularly in catalysis and corrosion processes.