Low-Dose 4D-STEM Tomography for Beam-Sensitive Nanocomposites

• Published in: ACS materials letters 2024-01, Vol.6 (1), p.165-173
• Main Authors: Hugenschmidt, Milena, Jannis, Daen, Kadu, Ajinkya Anil, Grünewald, Lukas, De Marchi, Sarah, Pérez-Juste, Jorge, Verbeeck, Johan, Van Aert, Sandra, Bals, Sara
• Format: Article
• Language: English
• ISSN: 2639-4979; 2639-4979
• DOI: 10.1021/acsmaterialslett.3c01042

Electron tomography is essential for investigating the three-dimensional (3D) structure of nanomaterials. However, many of these materials, such as metal–organic frameworks (MOFs), are extremely sensitive to electron radiation, making it difficult to acquire a series of projection images for electron tomography without inducing electron-beam damage. Another significant challenge is the high contrast in high-angle annular dark field scanning transmission electron microscopy that can be expected for nanocomposites composed of a metal nanoparticle and an MOF. This strong contrast leads to so-called metal artifacts in the 3D reconstruction. To overcome these limitations, we here present low-dose electron tomography based on four-dimensional scanning transmission electron microscopy (4D-STEM) data sets, collected using an ultrafast and highly sensitive direct electron detector. As a proof of concept, we demonstrate the applicability of the method for an Au nanostar embedded in a ZIF-8 MOF, which is of great interest for applications in various fields, including drug delivery.