Wavelet analysis of extended x-ray absorption fine structure data
Wavelet analysis of extended x-ray absorption fine structure data
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DOI：
10.1103/physrevb.71.094110
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发表时间：
2005-03-01
影响因子：
3.7
通讯作者：
Chukalina, M
中科院分区：
文献类型：
--
作者：
Funke, H;Scheinost, AC;Chukalina, M
傅里叶变换（FT）是扩展X射线吸收精细结构（EXAFS）谱数据处理和解释的基本步骤。FT通过后向散射原子与吸收原子（所谓的壳层）的径向距离来分离后向散射原子。我们建议通过小波变换（WT）常规地补充FT，其不仅提供径向距离分辨率，而且在k空间中解析。这些信息使原子的元素性质易于区分，特别是如果这些原子处于相同的距离。我们提出了一个深入的分析Morlet小波，它具有特定的优势EXAFS分析，包括可能性估计Morlet参数值优化元素或空间分辨率。使用Zn-Al层状双氢氧化物的实验光谱，我们证明了Al和Zn在相似的晶体位置的歧视，尽管破坏性干扰大大减少信号，信息。最后，扩展到多个散射路径导致更深入地了解小波变换的分辨率特性。
Fourier transform (FT) is a fundamental step for the data reduction and interpretation of extended x-ray absorption fine structure (EXAFS) spectra. The FT separates backscattering atoms by their radial distance from the absorbing atom (so-called shells). We suggest to routinely complement the FT by a wavelet transform (WT), which provides not only radial distance resolution, but resolves in k space. This information eases the discrimination of atoms by their elemental nature, especially if these atoms are at the same distance. We present an in-depth analysis of the Morlet wavelet, which has specific advantages for EXAFS analysis, including the possibility to estimate Morlet parameter values optimized either for elemental or for spatial resolution. Using an experimental spectrum of Zn-Al layered double hydroxide, we demonstrate the discrimination of Al and Zn at a similar crystallographic position, in spite of destructive interference substantially reducing signal, information. Finally, the extension to multiple scattering paths leads to a deeper understanding of the resolution properties of the WT.