Measurement and Modeling of Short and Medium Range Order in Amorphous Ta2O5 Thin Films.
Measurement and Modeling of Short and Medium Range Order in Amorphous Ta2O5 Thin Films.
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DOI：
10.1038/srep32170
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发表时间：
2016-08-26
影响因子：
4.6
通讯作者：
Mehta A
中科院分区：
文献类型：
--
作者：
Shyam B;Stone KH;Bassiri R;Fejer MM;Toney MF;Mehta A
无定形的薄膜和涂料在重要性上迅速增长，我们在这里不了解这些材料在原子尺度上的高质量结构数据放牧的X射线总散射测量值，以检查TA2O5膜的前50-100 nm的原子结构；下一代的重力波检测器的敏感性。结构信息介绍了包装和混乱机制的洞察力。基于扭结的TA-O-TA主链的主要结构单元的包装还发现，在这里研究的所有肌肉曲，不仅结晶不良，而且似乎缺乏真正的3D顺序。
Amorphous films and coatings are rapidly growing in importance. Yet, there is a dearth of high-quality structural data on sub-micron films. Not understanding how these materials assemble at atomic scale limits fundamental insights needed to improve their performance. Here, we use grazing-incidence x-ray total scattering measurements to examine the atomic structure of the top 50–100 nm of Ta2O5 films; mirror coatings that show high promise to significantly improve the sensitivity of the next generation of gravitational-wave detectors. Our measurements show noticeable changes well into medium range, not only between crystalline and amorphous, but also between as-deposited, annealed and doped amorphous films. It is a further challenge to quickly translate the structural information into insights into mechanisms of packing and disorder. Here, we illustrate a modeling approach that allows translation of observed structural features to a physically intuitive packing of a primary structural unit based on a kinked Ta-O-Ta backbone. Our modeling illustrates how Ta-O-Ta units link to form longer 1D chains and even 2D ribbons, and how doping and annealing influences formation of 2D order. We also find that all the amorphousTa2O5 films studied in here are not just poorly crystalline but appear to lack true 3D order.