Technologically relevant gas phase processes rely on reactants in vapor form for the production of thin films and nanoparticles. An instrument is described which enables the investigation of such vapors by x-ray absorption spectroscopy. Corresponding in situ studies provide information about gas phase precursor chemistry and optimized synthesis processes. The setup consists of a sealed vapor container heated by a hot air bath. Inert gas filling and temperature monitoring are implemented. Fluid dynamic simulations reveal a homogeneous temperature distribution without hot or cold spots. Temperature stability better than 1 K for at least 190 min allows time-dependent measurements or improved signal to noise ratios by averaging of datasets. Iron acetylacetonate is studied as a model system. X-ray absorption spectra measured by fluorescence are of high quality, allowing a detailed analysis of X-ray Absorption Near Edge Structure (XANES) and extended x-ray absorption fine structure. A molecular structure transformation is observed in XANES spectra of iron acetylacetonate vapor above 480 K probably due to the loss of one ligand. The setup allows the investigation of low volatility compounds with vapor pressures above 2 kPa at temperatures up to 520 K.

中文翻译：

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用于低挥发性化合物蒸气的 X 射线吸收光谱的原位池

技术相关的气相工艺依赖于蒸汽形式的反应物来生产薄膜和纳米颗粒。描述了一种能够通过 X 射线吸收光谱研究此类蒸气的仪器。相应的原位研究提供了有关气相前体化学和优化合成过程的信息。该装置由一个由热空气浴加热的密封蒸汽容器组成。实施惰性气体填充和温度监测。流体动力学模拟揭示了没有热点或冷点的均匀温度分布。至少 190 分钟的温度稳定性优于 1 K，允许进行时间相关测量或通过对数据集进行平均来提高信噪比。乙酰丙酮铁作为模型系统进行研究。通过荧光测量的 X 射线吸收光谱具有高质量，可以对 X 射线吸收近边结构 (XANES) 和扩展的 X 射线吸收精细结构进行详细分析。在 480 K 以上的乙酰丙酮铁蒸气的 XANES 光谱中观察到分子结构转变，这可能是由于失去了一个配体。该设置允许在高达 520 K 的温度下研究蒸气压高于 2 kPa 的低挥发性化合物。