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Abstract Mixtures of Ce‐doped rare‐earth aluminum perovskites are drawing a significant amount of attention as potential scintillating devices. However, the synthesis of complex perovskite systems leads to many challenges. Designing the A‐site cations with an equiatomic ratio allows for the stabilization of a single‐crystal phase driven by an entropic regime. This work describes the synthesis of a highly epitaxial thin film of configurationally disordered rare‐earth aluminum perovskite oxide (La0.2Lu0.2Y0.2Gd0.2Ce0.2)AlO3and characterizes the structural and optical properties. The thin films exhibit three equivalent epitaxial domains having an orthorhombic structure resulting from monoclinic distortion of the perovskite cubic cell. An excitation of 286.5 nm from Gd3+and energy transfer to Ce3+with 405 nm emission are observed, which represents the potential for high‐energy conversion. These experimental results also offer the pathway to tunable optical properties of high‐entropy rare‐earth epitaxial perovskite films for a range of applications.
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This content will become publicly available on December 1, 2025
Structural degeneracy and formation of crystallographic domains in epitaxial LaFeO3 films revealed by machine-learning assisted 4D-STEM
Abstract Structural domains and domain walls, inherent in single crystalline perovskite oxides, can significantly influence the properties of the material and therefore must be considered as a vital part of the design of the epitaxial oxide thin films. We employ 4D-STEM combined with machine learning (ML) to comprehensively characterize domain structures at both high spatial resolution and over a significant spatial extent. Using orthorhombic LaFeO3as a model system, we explore the application of unsupervised and supervised ML in domain mapping, which demonstrates robustness against experiment uncertainties. The results reveal the consequential formation of multiple domains due to the structural degeneracy when LaFeO3film is grown on cubic SrTiO3. In situ annealing of the film shows the mechanism of domain coarsening that potentially links to phase transition of LaFeO3at high temperatures. Moreover, synthesis of LaFeO3on DyScO3illustrates that a less symmetric orthorhombic substrate inhibits the formation of domain walls, thereby contributing to the mitigation of structural degeneracy. High fidelity of our approach also highlights the potential for the domain mapping of other complicated materials and thin films.
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- Award ID(s):
- 2011876
- PAR ID:
- 10513023
- Publisher / Repository:
- Springer Nature
- Date Published:
- Journal Name:
- Scientific Reports
- Volume:
- 14
- Issue:
- 1
- ISSN:
- 2045-2322
- Page Range / eLocation ID:
- 4198
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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