Abstract A novel in situ cell was developed for simultaneous X-ray absorption fine structure and X-ray diffraction (XAFS/XRD) measurements at high temperatures up to 1773 K in a gas atmosphere such as air containing reactive oxygen, in which typical heat-resistant or environmental-barrier materials are used. This new cell can provide multimodal information by combining the following complementary information: (a) chemical states of a specific element and the short-range order (SRO) structure around the atoms, via XAFS measurements, and (b) the long-range order (LRO) crystal structure, via XRD. In situ observation of XAFS/XRD is essential to characterize materials under severe conditions, because reactions sometimes accompany metastable states, and quenching high-temperature states down to room temperature is quite difficult. The performance of the new cell was checked by in situ XAFS/XRD observation of the phase transition of TiO2 from anatase to rutile. Then, the developed technique was applied to a new type of environmental-barrier coating material, Yb2Si2O7, which was exposed to heat cycles up to 1773 K in air. The bulk structure maintained the chemical state of Yb3+ and the crystal structure of Yb2Si2O7, and no reaction phase was observed. The developed technique could provide fundamental information to understand the behaviors of materials used at high temperatures.

中文翻译：

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开发用于在高温下同时进行 XAFS/XRD 测量的原位电池

摘要 开发了一种新型原位电池，用于在高达 1773 K 的高温下在含有活性氧的气体环境中同时进行 X 射线吸收精细结构和 X 射线衍射 (XAFS/XRD) 测量，其中典型的热-使用抗性或环境屏障材料。这种新电池可以通过结合以下补充信息来提供多模态信息：（a）特定元素的化学状态和原子周围的短程有序（SRO）结构，通过 XAFS 测量，以及（b）长程有序(LRO) 晶体结构，通过 XRD。XAFS/XRD 的原位观察对于在恶劣条件下表征材料至关重要，因为反应有时伴随着亚稳态，而将高温状态淬火至室温非常困难。通过对 TiO2 从锐钛矿到金红石的相变的原位 XAFS/XRD 观察来检查新电池的性能。然后，将开发的技术应用于新型环境阻隔涂层材料 Yb2Si2O7，该材料在空气中暴露于高达 1773 K 的热循环中。本体结构保持了Yb3+的化学状态和Yb2Si2O7的晶体结构，没有观察到反应相。所开发的技术可以提供基本信息，以了解在高温下使用的材料的行为。本体结构保持了Yb3+的化学状态和Yb2Si2O7的晶体结构，没有观察到反应相。所开发的技术可以提供基本信息，以了解在高温下使用的材料的行为。本体结构保持了Yb3+的化学状态和Yb2Si2O7的晶体结构，没有观察到反应相。所开发的技术可以提供基本信息，以了解在高温下使用的材料的行为。