| About this Abstract |
| Meeting |
2023 TMS Annual Meeting & Exhibition
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| Symposium
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Local Ordering in Materials and Its Impacts on Mechanical Behaviors, Radiation Damage, and Corrosion
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| Presentation Title |
Direct Observation of Local Ordering and Charge Distribution in High Entropy Oxides |
| Author(s) |
Lei Su, Huaixun Huyan, Abhishek Sarkar, Wenpei Gao, Xingxu Yan, Christopher Addiego, Robert Kruk, Horst Hahn, Xiaoqing Pan |
| On-Site Speaker (Planned) |
Xiaoqing Pan |
| Abstract Scope |
The enhanced compositional flexibility to incorporate multiple-principal cations in high entropy oxides (HEOs) offers the opportunity to expand boundaries for accessible compositions and unconventional properties in oxides. Attractive functionalities have been reported in some bulk HEOs, which are attributed to the long-range compositional homogeneity, lattice distortion, and local chemical bonding characteristics in materials. However, the intricate details of local composition fluctuation, metal-oxygen bond distortion and covalency are difficult to visualize experimentally, especially on the atomic scale. Here, we present the atomic structure-chemical bonding-property correlations in a series of perovskite-HEOs utilizing the recently developed four-dimensional scanning transmission electron microscopy techniques which enables to determine the structure, chemical bonding, electric field, and charge density on the atomic scale. The existence of compositional fluctuations along with significant composition-dependent distortion of metal-oxygen bonds is observed. Consequently, distinct variations of metal-oxygen bonding covalency are shown by the real-space charge-density distribution maps with sub-Å resolution. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Characterization, Electronic Materials, High-Entropy Alloys |