Structure Analysis Division,Testing Center, Institute of Metal Research, Chinese Academy of Science,Shenyang 110016,China.
Microsc Microanal. 2019 Jun;25(3):625-629. doi: 10.1017/S1431927619000230. Epub 2019 Mar 14.
The fluorescence effect induced by Kβ photons is usually so small that it can be neglected. However, in the Fe-Mn system, omitting Kβ fluorescence correction will lead to the overestimation of the Mn content especially when Mn is the minor alloy element. In this study, the error in the Mn concentration induced by Kβ fluorescence was investigated by both Monte Carlo simulation, using the pyPENELOPE program, and systematic electron probe measurements on the Fe-0.53% Mn alloy standard by the aid of CalcZAF software. It is shown that the error caused by Kβ fluorescence exceeds 4% for the Fe-0.53% Mn alloy. The problem can be overcome by utilizing CalcZAF in which β-line fluorescence has been included, or by employing a similar standard Fe-0.85% Mn for Mn in the absence of β-line fluorescence correction. In addition, a modified calibration curve method, using k-values instead of X-ray intensity as a variable, is presented and used to measure the Mn concentration. The accuracy of this method is as good as or better than that of the conventional matrix correction method. Compared with conventional calibration curve methods, it is time-saving because the k-value is not sensitive to instrument fluctuations and the established curve remains valid for a long period.
Kβ 光子引起的荧光效应通常很小，可以忽略不计。然而，在 Fe-Mn 体系中，如果忽略 Kβ 荧光校正，会导致 Mn 含量的高估，尤其是当 Mn 是次要合金元素时。本研究采用蒙特卡罗模拟（使用 pyPENELOPE 程序）和基于 CalcZAF 软件的系统电子探针测量，对 Fe-0.53%Mn 合金标准样品中 Kβ 荧光引起的 Mn 浓度误差进行了研究。结果表明，对于 Fe-0.53%Mn 合金，Kβ 荧光引起的误差超过 4%。通过利用 CalcZAF（其中包含 β 线荧光校正），或者在没有 β 线荧光校正的情况下，使用类似的标准 Fe-0.85%Mn 进行 Mn 校正，就可以克服这个问题。此外，还提出并使用了一种改进的校准曲线法，该方法使用 k 值而不是 X 射线强度作为变量，来测量 Mn 浓度。该方法的准确性与传统的基体校正法相当或更好。与传统的校准曲线方法相比，该方法省时，因为 k 值对仪器波动不敏感，并且建立的曲线在很长一段时间内仍然有效。
