Speaker
Description
Nanomaterials are important for a wide range of applications because of their unique properties, which are strongly connected to their three-dimensional (3D) structure. Electron tomography has therefore been used in an increasing number of studies. However, the increasing complexity of nanomaterials has driven the development of even more advanced 3D characterization techniques, which will be discussed in this contribution.
For example, 3D characterization of structural defects in nanoparticles by transmission electron microscopy is far from straightforward since the presence of diffraction contrast in a tilt series of images violates the projection requirement for tomography. However, being able to visualize defects is of great importance to understand e.g. the initial growth of metallic nanoparticles or the effect of pulsed laser irradiation on the crystal structure. By simultaneous acquisition of tilt series using different annular detectors, we were able to visualize both the morphology and the defect structure of several types of nanostructures [1,2]. Moreover, also a 3D characterization at the atomic scale could be performed.
In order to preserve the carefully designed morphologies and functionalities, understanding the stability of nanomaterials during application is of equal importance. It is hereby important to note that most electron tomography investigations have been performed under the conventional conditions of an electron microscope. An emerging challenge is therefore to fully understand the connection between the 3D structure and properties under realistic conditions, including high temperatures as well as in the presence of liquids and gases. Therefore, I will discuss novel methodologies to track the fast 3D changes of nanomaterials that occur under such conditions [3].
[1] N. Winckelmans et al., The Journal of Physical Chemistry C 122 (2018), p.13522
[2] J.D. Smith et al., Angewandte Chemie 59 (2020), p.943
[3] W. Albrecht et al. Accounts of Chemical Research, doi.org/10.1021/acs.accounts.0c00711
| Speaker Country | Belgium |
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