ELECTRON MICROPROBE ANALYSIS OF CONTENTS IN MINERALS OF THE TRANSITION ELEMENTS IONS WITH DIFFERENT VALENCIES

摘要

The concentration of transition elements ions (Fe,Mn) with different valency in minerals is determined by L_(#alpha#) lines. The intensities ratio of L_(#alpha#) lines in samples were measured at two different electron accelerating voltages (5 and 10 kV). This ratio mainly depends on the absorption coefficients. The comparisons between the experimental value of intensities ratio and the value computed by PAP model provides a means of determining the absorption coefficients. The absorption coefficients are determined in two points of spectrum: at the high energy side of the L_(#alpha#) line for which the L_(III) absorption edge overlaps of the L_(#alpha#) emission band and at the low energy side for which this absorption is absent. The difference of the absorption coefficients in these points provides a methods f detecting the magnitude of ion concentration.