In this paper, we employ atomic kinetic Monte Carlo (AKMC) simulations to get insight into the kinetics of Fe–Cr interdiffusion in nanometric multilayer materials, and the relevant information that can be extracted from the evolution of the experimental X-ray diffraction (XRD) spectrum. For this purpose, we develop an elastic model to obtain the interplanar spacing for a given composition profile derived from AKMC simulation, and then we simulate the corresponding XRD spectrum and compare it with the experimental one. We find a very good agreement between the two, which validates our modeling procedure. Then we put some effort into trying to relate specific features of the XRD spectra with phenomena occurring at the atomic scale, mostly the decay of satellite peak intensities over time. The interdiffusion coefficients extracted from the XRD spectra are underestimated in the Fe-rich phase and overestimated in the Cr-rich phase, but more or less within one order of magnitude of the values obtained from standard measurements. Extracting more quantitative kinetic information directly from the experimental XRD spectra is rather difficult without resorting to a modeling study.

中文翻译：

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从热退火超晶格的 XRD 光谱中测量相互扩散系数：Fe-Cr 纳米多层膜的建模和实验相结合的研究


在本文中，我们采用原子动力学蒙特卡洛 （AKMC） 模拟来深入了解纳米多层材料中 Fe-Cr 相互扩散的动力学，以及可以从实验 X 射线衍射 （XRD） 光谱的演变中提取的相关信息。为此，我们开发了一个弹性模型，以获得从 AKMC 模拟得出的给定成分剖面的面间距，然后我们模拟相应的 XRD 光谱并将其与实验光谱进行比较。我们发现两者之间有非常好的一致性，这验证了我们的建模过程。然后，我们付出了一些努力，试图将 XRD 光谱的特定特征与原子尺度上发生的现象联系起来，主要是卫星峰值强度随时间的衰减。从 XRD 光谱中提取的相互扩散系数在富铁相中被低估，在富铬相中被高估，但或多或少与从标准测量中获得的值相差一个数量级。如果不求助于建模研究，直接从实验 XRD 光谱中提取更多定量动力学信息是相当困难的。