EDS is also known as Energy-dispersive X-ray spectroscopy. This technique is used for the chemical characterization of the sample. It is applicable for the elements with atomic number more than boron.
Principle of Operation
When the electron beam interacts with the sample, it generates X-ray fluorescence as shown in figure. The energy of each photon is the representative of the elements present in the sample. The Energy Dispersive spectrometer collects the X-rays and plots them as counts versus energy curve. It indentifies and labels the elements responsible for the peaks in this energy distribution.
Different modes of analysis
Chemical concentration map (elemental mapping)
Factors affecting signal collection
Beam energy (keV)
Take off angle
Point EDAX represents the elements present/compositional analysis of a particular point. It may be a single point or multi point analysis. One point or multi points are selected from the bulk sample and it shows the element presents in that selected point/points.
Fig. Point analysis shows the presence of W,Cr,Y,O
Line EDAX represents the elements present/compositional analysis of a selected line. It gives the idea about the line profile means the compositional information along the line.
Fig. Lline analysis shows the presence of W,Cr,Y,O
Elemental mapping gives the overall distribution of all the elements in the sample.
Fig X-ray elemental mapping shows the presence of W,Cr,Y.