SEM with EDX/EDS

Purpose

Imaging of a surface at high magnification, combined with the ability to immediately measure the elemental composition on interesting areas or in small details found on the surface, provides a very useful method for solving many types of problems and the method is often used for failure analysis. It can for example be used for analysis of fracture surfaces, for identification of contaminants, deposits or discolorations on a surface, for measuring and identification of thin layers, for detection of micro cracks or defects in a material, for imaging, measuring and identifying small details like particles or fibres, and much more. The depth of field is very large, giving sharp images even with large variations in topography. This makes SEM an advantageous tool even for low magnification imaging. 

With energy dispersive X-ray analysis (EDX), sometimes referred to as energy dispersive spectroscopy (EDS), the elemental composition can be measured on a selected area of a surface or of small details such as particles, fibres, etc. EDX mapping results in images giving information about the lateral distribution of each individual element over an analysed surface.

SEM/EDX is a very useful method for failure analysis. Analysis of surfaces can provide answers to questions related to surface structure, microcracks, contaminants, deposits, discoloration, etc. Analysis of prepared cross sections can be performed with respect to microcracks, porosity, thin layers, inclusions, etc. Analysis of individual particles, flakes, fibres, materials scraped from a surface, etc. can provide answers both about appearance such as size, shape, surface structure, etc. and elemental composition.

Method

Analysis can be performed of all types of solid materials, both electrically conductive and insulating. The depth of analysis is on the order of 1 µm and the analysis is done in vacuum.

An insulating material is often coated with a thin, electrically conductive layer of, for example, gold/palladium to avoid charging effects of the sample during analysis. The layer is so thin that it does not affect the analysis results. Another way to analyse insulating samples is in low vacuum. In that case the sample does not need to be coated with an electrically conductive layer.

A cross section of a sample can be prepared by embedding of the sample in epoxy or thermosetting resin, followed by grinding and polishing with great precision.

Deliveries

Results will be delivered as a report with enclosed SEM photos and analysis results with interpretations and explanations. Only SEM photos can also be delivered in cases where a formal report is not necessary.