Investigation of thermal treatment effects on deviatoric strain and defect structure in yttria-stabilized zirconia via synchrotron X-ray microdiffraction 2D mapping

초록

In the field of oxide electronics, the crystalline quality and local strain distribution of single-crystal substrates are critical factors that directly dictate the performance of epitaxially grown functional devices. However, the methods used for evaluating the crystal quality at the microscale have limitations. For example, electron microscopy provides only local information, and conventional X-ray diffraction yields only an ensemble average of the entire crystal. Laue diffraction using a focused X-ray beam serves as a powerful alternative. In this study, we conducted synchrotron X-ray microdiffraction experiments on yttria-stabilized zirconia substrates before and after thermal annealing, utilizing the 4B beamline at the Pohang Accelerator Laboratory, Pohang, Republic of Korea, which delivers a polychromatic X-ray beam spanning approximately 5-25 keV (lambda approximate to 0.05-0.25 nm). The deviations in Laue patterns generated by white-beam synchrotron radiation were determined to index and refine the crystal orientation and deviatoric strain. Two-dimensional mapping was performed to directly visualize the quality of both as-grown and thermally treated crystals by analyzing the internal strain tensor, which revealed their crystallinity and defect density. This technique offers a powerful and effective solution for characterizing epitaxially grown films or superlattices, facilitating advancements in oxide electronics and epitaxial thin-film metrology.

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