The increasing demand for energy, foods, and medicines has encouraged the search for new materials. In this context, nanostructured materials have gained attention due to their unique properties in comparison with bulk counterparts. The comprehension of atom mobility under different processing and operating conditions is a topic that impacts different fields, such as catalysis and self-healing materials. In catalysis, atom mobility is directly related to performance, since the atom migration leads to the sintering of metallic particles and loss of catalytic activity. For self-healing systems, atom mobility is a crucial point to be highlighted, since to avoid the complete rupture, it is needed that the healing agents migrate towards the damage, filling it faster than the propagation of the crack. For both applications, better comprehension depends on adequate characterization tools, with spatial and, if available, temporal resolution. In this context, transmission electron microscopy is a powerful technique that includes imaging, spectroscopy, and crystallographic analyses, and the correction of spherical aberration (AC-TEM) has boosted the resolution of images, improving the quality of the analysis at the atomic scale. This project proposes a deep characterization of metals (Au, Ni, Fe) supported on ZrO2 thin-films by electron energy loss spectroscopy (EELS), selected-area electron diffraction (SAED), as well as direct visualization of the modification of the samples by in situ AC-TEM analysis. The in situ measurements allow a deep understanding of atom mobility in real-time, as well as provide insights into the driving force for atom migration.
News published in Agência FAPESP Newsletter about the scholarship: