Quasi-In Situ 4D-STEM Mapping of Exsolution Driven Parent Matrix Restructuring in Sr2FeMoO6-δ

elib (German Aerospace Center)

Abstract

The in situ exsolution of catalytic particles upon reduction makes double-perovskites promising candidates for next-generation solid oxide cells (SOCs). While recent in situ S/TEM studies have –visualized this process, these investigations have primarily focused on isolated particles rather than realistic electrode architectures and the effect of exsolution on the surrounding host matrix remains largely unexplored. Herein, a quasi-in situ S/TEM approach is presented to investigate the impact of exsolution on a realistic Sr 2 FeMoO6-δ (SFM) electrode by decoupling the influence of electron-beam-induced artifacts. By extracting a lamella from a bulk SOC using a plasma-FIB and performing identical-location characterization utilizing EDS and 4D-STEM before and after reduction captures both the chemical segregation and intrinsic structural transformations within the electrode grains. Utilizing iDPC and radial Fourier analysis (RFA), this approach reveals that surface exsolution is coupled with substantial crystallographic reorganization within the SFM matrix, evidenced by distinct domain shrinkage and localized phase gradients along grain facets. The interconnected bulk electrode geometry promotes higher exsolution density compared to isolated powder particles, underscoring the necessity of studying realistic architectures. By linking surface exsolution to matrix modification in a realistic bulk electrode geometry, this quasi-in situ methodology provides a vital insights into the exsolution process.

Authors 8

1. Pritam Kishore Chakraborty Aachen Institute of Physical Chemistry

   Forschungszentrum Jülich · RWTH Aachen University

   Affiliation as printed

   Institute of Energy Technology-Fundamental Electrochemistry (IET-1) , Forschungszentrum Jülich GmbH , Jülich , Germany

   Institute of Physical Chemistry , RWTH Aachen University , Aachen , Germany

2. Junbeom Park

   Forschungszentrum Jülich

   Affiliation as printed

   Institute of Energy Technology-Fundamental Electrochemistry (IET-1) , Forschungszentrum Jülich GmbH , Jülich , Germany

3. Stephanie E. Wolf

   Forschungszentrum Jülich · Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)

   Affiliation as printed

   DLR Institut für Technische Thermodynamik , Stuttgart , Baden-Württemberg , Germany

   Institute of Energy Technology-Fundamental Electrochemistry (IET-1) , Forschungszentrum Jülich GmbH , Jülich , Germany

4. Vaibhav Vibhu

   Forschungszentrum Jülich

   Affiliation as printed

   Institute of Energy Technology-Fundamental Electrochemistry (IET-1) , Forschungszentrum Jülich GmbH , Jülich , Germany

5. Hongyu Sun

   Denssolutions (Netherlands)

   Affiliation as printed

   DENSsolutions B.V. , Informaticalaan , Delft , Netherlands

6. Hugo Pérez Garza
7. Shibabrata Basak

   Forschungszentrum Jülich

   Affiliation as printed

   Institute of Energy Technology-Fundamental Electrochemistry (IET-1) , Forschungszentrum Jülich GmbH , Jülich , Germany

8. Rüdiger‐A. Eichel