Monte Carlo Study of Quantitative Electron Probe Microanalysis of Monazite with a Coating Film: Comparison of 25 nm Carbon and 10 nm Gold at E0= 15 and 25 keV
Monte Carlo Study of Quantitative Electron Probe Microanalysis of Monazite with a Coating Film: Comparison of 25 nm Carbon and 10 nm Gold at E0= 15 and 25 keV
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DOI：
10.1111/j.1751-908x.2007.00852.x
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发表时间：
2007-06
影响因子：
3.8
通讯作者：
Takenori Kato
中科院分区：
文献类型：
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作者：
Takenori Kato
碳（厚度为25-30 nm）是地质样品的电子探针显微分析（EPMA）中最常用的涂层材料。在特殊情况下，也可以使用金涂层来减少电子轰击对表面的损伤。MonteCarlo模拟已经进行了独居石与25 nm的碳和10 nm的金涂层，以了解在定量EPMA在E0= 15 keV和25 keV的涂层膜的效果。模拟表明，碳涂层独居石在独居石中产生的X射线的深度分布与未涂层独居石相同，而金涂层独居石产生了扭曲的深度分布。在40度的X射线发射角下，10 nm的金涂层在独居石和纯钍之间的k比率比25 nm的碳涂层高1.06（15 keV）和1.05（25 keV）倍。因此，10 nm的金涂层是导致独居石定量EPMA不准确的可能因素，而25 nm的碳涂层没有显著影响。
Carbon (25–30 nm in thickness) is the most common coating material used in the electron probe microanalysis (EPMA) of geological samples. A gold coating is also used in special cases to reduce the surface damage by electron bombardment. Monte Carlo simulations have been performed for monazite with a 25 nm carbon and a 10 nm gold coating to understand the effect of a coating film in quantitative EPMA at E0= 15 keV and 25 keV. Simulations showed that carbon‐coated monazite gave the same depth distribution of the generated X‐rays in the monazite as uncoated monazite, whilst gold‐coated monazite gave a distorted depth distribution. A 10 nm gold coating was 1.06 (15 keV) and 1.05 (25 keV) times higher in k‐ratio between monazite and pure thorium than a 25 nm carbon coating at an X‐ray take‐off angle of 40 degrees. Thus, a 10 nm gold coating is a possible factor contributing to inaccuracy in quantitative EPMA of monazite, while a 25 nm carbon coating does not have a significant effect.