Seminars Archive

Advanced microscopy methods for studying the nucleation and growth dynamics of nanostructures and interfaces in functional materials

Abstract
The mechanisms controlling the nucleation and early growth stages of nanoparticles and interfaces are in many cases difficult to assess. The use of spatially resolved Analytical Electron Microscopy (AEM) has revolutionised the characterization and understanding of nanostructures and interfaces in materials by providing atomic-scale structural and chemical information. This advanced microscopy approach typically combines Scanning Transmission Electron Microscopy (STEM) with two spectroscopic techniques, the Energy Dispersive X-ray Spectroscopy (EDXS) and Electron Energy-Loss Spectroscopy (EELS). Nowadays, modern probe aberration-corrected STEMs with the electron probe size below 1 Å allow simultaneous performance of atomic resolution imaging and spectroscopy of nanostructures and associated structural defects. Furthermore, the use of in situ microscopy for the dynamic investigations of nanomaterials in their native environments at the highest spatial resolution allows for faster progressing in the development of novel functional nanomaterials in the lab environment. To bridge the gap between conventional (high-vacuum) and in-situ liquid TEM we have recently implemented an interdisciplinary research platform for dynamic TEM studies in liquid environments that are overcoming the static limitations of conventional analysis techniques. Within the platform case-by-case specialized experiments can be created and implemented by proper redesign of liquid chambers. This approach allows performing direct nucleation and growth studies of nanoparticles either from solutions or during the electrodeposition at the nanoscale and in real time. In the presentation, the above described analytical capabilities will be discussed through the perspective of high-resolution AEM studies performed on different complex nanostructures and interfaces. Among the studied materials, the targeted drug delivery systems, hard magnets with their grain boundary structures, planar faults formation mechanism in perovskites, and the assessment of the plasmonic nanoparticles nucleation from aqueous solutions under dynamic conditions will be covered-