Zhou, J., Wong, N. L. M., Tan, H. R., Lin, M., Wei, F., Yang, P., Liew, S. L., Chai, J., Ngo, A. C. Y., & Wang, S. (2025). Highly thermally stable epitaxial high-entropy fluorite oxide thin films. Applied Physics Letters, 127(22). https://doi.org/10.1063/5.0295899
Abstract:
While high-entropy fluorite oxides have shown promise for applications in extreme environments, achieving epitaxial integration with high thermal stability and structural coherence remains a significant challenge. Here, we report the synthesis of an epitaxial chemically disordered single-phase fluorite oxide thin film, (HfZrCeGdCa)O2, on a yttria-stabilized zirconia (YSZ) (100) substrate via pulsed laser deposition. Structural characterization by x-ray diffraction (XRD) and atomic-resolution scanning transmission electron microscopy imaging and energy-dispersive x-ray spectroscopy confirm the high crystalline quality and uniform elemental distribution of the film, validating its chemically disordered single-phase character. In situ temperature-dependent XRD shows the high thermal stability without phase separation and secondary phase formation up to 1200 °C. Reciprocal space mapping and strain analysis indicate coherent in-plane lattice matching with the YSZ substrate, accompanied larger out-of-plane lattice constant. Local lattice tilting, rotation, and interfacial dislocations are observed, suggesting partial strain relaxation close to the interface. These results underscore the structural integrity and thermal stability of the chemically disordered single-phase fluorite oxide films, supporting their potential use in advanced functional coatings for extreme environments.
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Funding Info:
This research is supported by core funding from: Mat-GDT (Materials − Generative Design Testing) Framework
Grant Reference no. : M24N4b0034
This research is supported by core funding from: Future Energy Acceleration & Translation (FEAT), Strategic Research & Translation Thrust (SRTT)
Grant Reference no. : n.a.
Description:
This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Zhou, J., Wong, N. L. M., Tan, H. R., Lin, M., Wei, F., Yang, P., Liew, S. L., Chai, J., Ngo, A. C. Y., & Wang, S. (2025). Highly thermally stable epitaxial high-entropy fluorite oxide thin films. Applied Physics Letters, 127(22) and may be found at https://doi.org/10.1063/5.0295899