Single-Ion Deconvolution of Mass Peak Overlaps for Atom Probe Microscopy
Single-Ion Deconvolution of Mass Peak Overlaps for Atom Probe Microscopy
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DOI：
10.1017/s1431927616012782
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发表时间：
2017-04-01
影响因子：
2.8
通讯作者：
Moody, Michael P.
中科院分区：
文献类型：
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作者：
London, Andrew J.;Haley, Daniel;Moody, Michael P.
由于所研究材料的固有蒸发特性、质量分辨能力不足以及缺乏入射离子动能的知识，原子探针质荷比谱中的峰可能重叠并导致不正确的组成测量。这些峰重叠的贡献可以在全球范围内去卷积，通过简单地检查相邻的峰结合自然同位素丰度的知识。然而，该策略没有考虑到对该卷积信号的相对贡献通常在分析体积的不同区域中显著变化的事实;例如，跨接口和群集。在重建中可以很容易地识别离散的微观结构区域的情况下，空间局部化反卷积已经取得了一些进展，但这意味着不可能进行进一步的点云分析。因此，我们提出了一个离子的方法，其中每个离子的身份，通常掩盖峰重叠，通过检查其周围环境的同位素丰度来解决。由此产生的峰值去卷积数据是一个点云，可以用任何现有的工具进行分析。我们提出了两个详细的案例研究和讨论这种新技术的局限性。
Due to the intrinsic evaporation properties of the material studied, insufficient mass-resolving power and lack of knowledge of the kinetic energy of incident ions, peaks in the atom probe mass-to-charge spectrum can overlap and result in incorrect composition measurements. Contributions to these peak overlaps can be deconvoluted globally, by simply examining adjacent peaks combined with knowledge of natural isotopic abundances. However, this strategy does not account for the fact that the relative contributions to this convoluted signal can often vary significantly in different regions of the analysis volume; e.g., across interfaces and within clusters. Some progress has been made with spatially localized deconvolution in cases where the discrete microstructural regions can be easily identified within the reconstruction, but this means no further point cloud analyses are possible. Hence, we present an ion-by-ion methodology where the identity of each ion, normally obscured by peak overlap, is resolved by examining the isotopic abundance of their immediate surroundings. The resulting peak-deconvoluted data are a point cloud and can be analyzed with any existing tools. We present two detailed case studies and discussion of the limitations of this new technique.