USE OF EVAPORATED METAL FILM STANDARDS IN THIN LAYER X-RAY FLUORESCENCE ANALYSIS OF MIXED OXIDES

Thin evaporated metal films (atomic number range 24 to 50), have been employed as standards in X-ray fluorescence analysis of metal oxides. A linear relationship between excited X-ray intensity and element concentration has been observed for film thicknesses up to about 0·1 mg cm-2, indicating that in this region absorption effects have no observable influence on the X-ray intensity. Having established mass concentration-X-ray intensity ratios for different elements, the subsequent analysis of mixed oxides containing these elements is extremely rapid, since repeated calibrations are unnecessary. The standard deviation in analysis of known mixtures containing iron, nickel and chromium oxides is found to be less than 3%.