Applicability of the differential X-ray absorption method to the determinations of foil thickness and local composition in the analytical electron microscope

Abstract

In this paper, we examine the applicability of the differential X-ray absorption (DXA) method of Morris, Ball and Statham which is capable of determining foil thickness and local composition concurrently in an analytical electron microscope. The method is first modified to take a general form where the thickness determination is achieved with a pair of characteristic lines from different elements. When this form is used, the pair is not necessarily limited from the same elements. It is shown then that there are four important factors affecting the precision and accuracy of the foil thickness. A comparison is carried out between the thicknesses determined with the DXA method and those measured with the convergent-beam electron diffraction method. The composition analysed with the DXA method is also compared with the nominal composition of the sample.