Compensating Local Magnifications in Atom Probe Tomography for Accurate Analysis of Nano-Sized Precipitates
Compensating Local Magnifications in Atom Probe Tomography for Accurate Analysis of Nano-Sized Precipitates
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DOI：
10.1017/s1431927621000180
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发表时间：
2021-03
影响因子：
2.8
通讯作者：
R. Lawitzki;P. Stender;G. Schmitz
中科院分区：
文献类型：
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作者：
R. Lawitzki;P. Stender;G. Schmitz
摘要 摘要 原子探针断层扫描（APT）中由具有异质蒸发行为的多相材料引起的局部放大伪影是一个众所周知的问题。特别是，对小沉淀物的精确尺寸、形状和成分的分析并非微不足道。我们对 APT 测量进行了数值模拟，以预测具有对比蒸发阈值的沉淀物的重建形态。基于避免粗晶化的统计方法，对模拟数据进行评估，以开发计算沉淀物原始尺寸的模型。该模型根据铁素体合金中具有较高和较低蒸发场的沉淀物的实验 APT 数据进行了测试。通过透射电子显微镜的补充研究证明了精确的尺寸。我们进一步展示了如何使用尺寸信息来获取最小沉淀物的成分信息，并提出一种新的方法来确定 APT 重建的正确深度缩放，以防不存在有关样本的互补几何信息或重建中看不到晶格平面。
Abstract Abstract Local magnification artifacts in atom probe tomography (APT) caused by multiphase materials with heterogeneous evaporation behavior are a well-known problem. In particular, the analysis of the exact size, shape, and composition of small precipitates is, therefore, not trivial. We performed numerical simulations of APT measurements to predict the reconstructed morphology of precipitates with contrasting evaporation thresholds. Based on a statistical approach that avoids coarse graining, the simulated data are evaluated to develop a model for the calculation of the original size of the precipitates. The model is tested on experimental APT data of precipitates with a higher and lower evaporation field in a ferritic alloy. Accurate sizes, proven by a complementary investigation by transmission electron microscopy, are obtained. We show further, how the size information can be used to obtain compositional information of the smallest precipitates and present a new methodology to determine a correct in-depth scaling of the APT reconstruction in case no complementary geometric information about the specimen exists or if no lattice planes are visible in the reconstruction.