QUANTITATIVE X-RAY-MICROANALYSIS IN ANALYTICAL ELECTRON-MICROSCOPY

This paper presents an overview of the principles and procedures for t he quantitative X-ray microanalysis of thin specimens using an analyti cal electron microscope (AEM) equipped with an energy dispersive X-ray spectrometer (EDS). The factors affecting the reliability of the quan tification are also summarized. The quantitative X-ray microanalysis w ith the AEM-EDS system is effective for the composition determination, the thickness determination and the site-occupancy determination. For the compositional determination, the Cliff-Lorimer ratio method is in troduced. A special emphasis is placed on the k-factor determination a nd the absorption correction to enhance reliability of the quantificat ion. For the thickness determination, it is illustrated that there are two primary procedures with the AEM-EDS system: one is to make use of the proportionality between the X-ray intensity and the thickness and the other is to take advantage of the difference between the magnitud es of X-ray absorption in the specimen. For the site-occupancy determi nation, the AL-CHEMI (atom location by channeling enhanced microanalys is) technique is described. A general form of an equation is presented , which can encompass various premises on the antisite occupation of h ost elements. It is shown that an error may be introduced from the del ocalization effect in the quantification, and some correction procedur es for this effect are suggested.