Center for Functional Nanomaterials Seminar

In recent years there have been many developments in electron microscopy that have pushed the spatial resolution and sensitivity to the single atom level for imaging, diffraction and spectroscopy. These capabilities have significantly extended our understanding of materials properties, particularly in the realm of nanoscale materials. 2-dimensional high resolution TEM for example, has produced astonishing images of atomic arrangements in advanced materials, while the experimental tools for 3-dimensional tomographic reconstructions are most advanced in the life sciences. The burgeoning field of nanotechnology ensures that electron microscopy will be a scientific method at the forefront of materials science for the foreseeable future. However, throughout these rapid advancements in technology, and all the insights that have resulted from them, one area that has remained largely untapped has been the ability to measure the atomic scale properties of materials and biological specimen on very short timescales (10-9-10-15s).
A first talk will focus on the advances in 2D and 3D electron microscopy. A second talk will present the experimental range that could conceivably be reached by a transmission electron microscope (TEM) operating using very short pulse durations and a high repetition rate. Such a TEM could be used for important materials research areas such as reaction dynamics related to catalysis and surface adsorption, atomic re-arrangements relevant to phase transformations and structural changes occurring upon heating, and domain switching in ferroelectrics. The experimental opportunities for the life sciences are different and will require special instrumental developments.
The challenges encountered while advancing from 2-dimensional towards 4-dimensional electron microscopy will be discussed by showing a variety of specific examples from the materials and the life sciences. Furthermore, the present limitations and capabilities of the current state-of-th