Abstract
The X-ray fluorescence analysis using the glass bead technique was applied for the determination of major components (La, Sr, Cu, Ba, Ni, Y, Zn, Bi, Pb, Ca, Tl, Nd and Ce) in small samples of various oxide superconductors. A Pt-5%Au crucible newly designed for small amounts of samples was employed for melting and casting vessel. Ten milligrams of sample was fused with 500mg of sodium tetraborate containing 20 mass % of lithium carbonate for the analysis of La and Y system superconductors. Five hundred mg sodium tetraborate containing 15 mass % of lithium hydroxide and 500mg of lithium tetraborate containing 10 mass % of lithium carbonate were used for Bi and Nd system one, respectively. For the analysis of Tl system one, in which Tl2O3 has a low boiling point and toxicity, 1500mg of sodium disulfate containing 12 mass % of sodium tetraborate was superior in fusing at a low temperature (ca. 400°C). The synthetic calibration standards were prepared with each oxide prefused with a fusing mixture, which contained 10 mass % of an analyte. The effect of coexisting elements were corrected with the theoretical alpha coefficients correction method. The relative standard deviations (RSDs) of repetitive seven measurements for the determined values of each analyte were less than 1%. The analytical values of various samples were in good agreement with those obtained by chemical analysis.
