A well designed compact furnace has been designed for in situ X‐ray absorption spectroscopy (XAS). It enables various heat ramps from 300 K to 1473 K. The furnace consists of heaters, a quartz tube, a circulated refrigerator and a power controller. It can generate ohmic heating via an induction process with tantalum filaments. The maximum heating rate exceeds 20 K min⁻¹. A quartz tube with gas feedthroughs allows the mixing of gases and adjustment of the flow rate. The use of this compact furnace allows in situ XAS investigations to be carried out in transmission or fluorescence modes under controlled temperature and atmosphere. Moreover, the furnace is compact, light and well compatible to XAS. The furnace was used to study cationic oxidation states in Pr₆O₁₁ and NiO compounds under elevated temperature and reduced atmosphere using the in situ X‐ray absorption near‐edge structure (XANES) technique at beamline 5.2 SUT‐NANOTEC‐SLRI of the Synchrotron Light Research Institute, Thailand. At room temperature, Pr₆O₁₁ contains a mixture of Pr³⁺ and Pr⁴⁺ cations, resulting in an average oxidation state of +3.67. In situ XANES spectra of Pr (L₃‐edge) show that the oxidation state of Pr⁴⁺ cations was totally reduced to +3.00 at 1273 K under H₂ atmosphere. Considering NiO, Ni²⁺ species were present under ambient conditions. At 573 K, the reduction process of Ni²⁺ occurred. The Ni⁰/Ni²⁺ ratio increased linearly with respect to the heating temperature. Finally, the reduction process of Ni²⁺ was completely finished at 770 K.

中文翻译：

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紧凑型原位X射线吸收光谱炉：Pr6O11和NiO中阳离子氧化态的设计，制造和研究

设计精良的紧凑型炉用于原位X射线吸收光谱（XAS）。它可以实现从300 K到1473 K的各种热梯度。该熔炉由加热器，石英管，循环式冰箱和电源控制器组成。它可以通过感应过程用钽丝产生欧姆加热。最大加热速率超过20 K min ^-1。带有气体穿通管的石英管可以混合气体并调节流量。使用这种紧凑型熔炉可以在受控的温度和气氛下以透射或荧光模式进行原位XAS研究。此外，该炉结构紧凑，轻巧，并且与XAS完全兼容。该炉用于研究Pr中的阳离子氧化态在泰国同步加速器光研究所的束线5.2 SUT-NANOTEC-SLRI处，使用原位X射线吸收近边缘结构（XANES）技术在高温和减少的气氛下₆ O ₁₁和NiO化合物。在室温下，Pr ₆ O ₁₁包含Pr ³⁺和Pr ⁴⁺阳离子的混合物，平均氧化态为+3.67。Pr（L ₃边）的原位XANES光谱表明，在H ₂气氛下，在1273 K下，Pr ⁴⁺阳离子的氧化态被完全还原为+3.00 。考虑到NiO，Ni ²⁺种在环境条件下存在。在573 K时，发生Ni ²⁺的还原过程。Ni ⁰ / Ni ^2+的比例相对于加热温度线性增加。最后，Ni ²⁺的还原过程在770 K下完全完成。