2021 年 38 巻 3 号 p. 380303-
This paper proposes a method to process the X-ray fluorescence spectra and evaluate the X-ray fluorescence intensity ratio of liquid alloys using X-ray fluorescence analysis. Pure Sn, Bi, and Sn-Bi alloys (Sn-20, 40, 60, and 80 atomic percentages of Bi) heated at 548 K in a crucible were irradiated using X-rays to obtain spectra at an optimal detection angle and optimal distance between the X-ray source and the sample. Aluminum foil was placed above the sample and used as the thermal protection material for the X-ray source. The obtained spectra were processed using function fitting to subtract the background, and the peak areas of Lα and Lβ emission line of Bi (Bi Lα and Lβ) were calculated as the Bi Lα and Lβ intensity, respectively. The quartic and Gaussian functions were determined to be optimum for calculating the background and the peak areas, respectively. The values for the fitted peaks of the spectra agreed with the energy values of the peak and reliable determination values. Further, the experimental Bi Lα/Lβ intensity ratios were calculated from the measured intensities. The ratios increased with Bi concentration. This increase could be explained using the predicted value, which was obtained using a formula considering X-ray absorption, X-ray fluorescence generation, and the distance dependence of the intensity.