A method to eliminate the background in X-ray diffraction patterns of oriented clay mineral samples

Abstract

AbstractA method is described for calculating, and then subtracting, the background from X-ray diffraction patterns of oriented clay mineral samples. Ti-Kα radiation is used and, to minimize the absorption of this radiation by air, a vacuum and helium-flushed device has been developed. This device can be used with other X-ray sources, offering a considerable increase of intensity—e.g. Co-Kα radiation is increased by 125%. With the background-eliminated patterns a better semi-quantitative estimate of the composition of clay mineral mixtures is possible. Small differences in composition of two samples can be identified by subtracting one of the background-eliminated patterns from the other. Using this method, peak maxima of smectite-group minerals can also be accurately determined.