4D-STEM: a powerful technique to study electron-beam-sensitive materials in the transmission electron microscope

• Grant number: 22/11161-4
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: March 01, 2023
• End date: February 29, 2024
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Edson Roberto Leite
• Grantee: Tanna Elyn Rodrigues Fiuza
• Supervisor: Rafal Edward Dunin-Borkowski
• Host Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Ministério da Ciência, Tecnologia e Inovação (Brasil). Campinas , SP, Brazil
• Institution abroad: Forschungszentrum Jülich, Germany
• Associated to the scholarship: 21/10672-2 - Correlating catalysis and self-healing in ceramics: Investigating metal mobility on ZrO2 thin-films by in-situ high-resolution transmission electron microscopy at the atomic scale, BP.PD

Abstract

The constant demand for new materials and the enhancement of their properties have been boosted by the upgrading of characterization tools. Among them, transmission electron microscopy (TEM) has been highlighted due to the possibility of joining images with spectroscopic and structural analyses. Additionally, the improvement of atomic resolution by spherical aberration correction and the development of in situ sample holders have been crucial for unveiling new materials and behaviors. Recently, the development of new cameras (CCD or direct detector) with a high dynamic range for scanning TEM has allowed the collection of four-dimensional data from different samples, including those sensitive to the electron beam. The 4D data is a 2D spatial image in which each pixel has an image of the electron scattering in the reciprocal space (2Dx2D). This way, the 4D data are rich in information, including signatures of the local structure, orientation, deformation, and electromagnetic fields. We intend to study the role of small amounts of Sn in ITO nanoparticles in the ITO sintering compared with the pure In2O3. We expect that the 4D-STEM experiment will shed light on the sintering at the nanoscale, for instance, if there are grains that preferentially induce the pore elimination while others halt the densification. We will also study a sample sensitive to the electron beam, with great difficulty obtaining results with conventional STEM. As an exciting example, we intend to study hybrid perovskites (focusing on surface stability and structural details) since they have technological importance for solar cells. The study of two different systems will allow the implementation of the 4D-STEM technique at LNNano for intern and extern users from the microscopy facilities for a wide range of samples. The BEPE at ER-C will provide the expertise needed to carry out the project since the host group has high knowledge in the 4D-STEM data analysis and processing. (AU)