Energy Dispersive X-ray Spectroscopy (EDS / EDX) for Scanning Electron Microscopes (SEM)


For Scanning Electron Microscopes (SEM), we offer a complete EDS (EDX) system: software,  SDD detector, digital signal processor and software. Our all-inclusive, high-end, Windows®-10 based software suite – Iridium Ultra – features a myriad of spectra, mapping, imaging, and advanced automation analysis tools. IXRF Systems’ SEM-EDS packages deliver premium detector technology as well as both  industry-leading and unique (to IXRF) features. No-cost software upgrades are included for the life of the system, so the analyst is never out of date.

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Energy-dispersive X-ray spectroscopy (EDS, EDX, EDXS or XEDS), sometimes called energy dispersive X-ray analysis (EDXA) or energy dispersive X-ray microanalysis (EDXMA), is an analytical technique used for the elemental analysis or chemical characterization of a sample. It relies on an interaction of an electron beam (e beam) and a sample within a Scanning Electron Microscope (SEM) instrument. Its characterization capabilities are due in large part to the fundamental principle that each element has a unique atomic structure allowing a unique set of peaks on its electromagnetic emission spectrum (which is the main principle of spectroscopy). The peak positions are predicted by the Moseley’s law with accuracy much better than experimental resolution of a typical EDX instrument.


Spectra Overview

  • Identifying Elements
  • Spectrum Processing
  • Annotations
  • Spectrum Overlay
  • Spectrum Reporting

Identify Elements

Kα Energy Markers help easily identify elemental peaks

Identify elements through cursor ID by selecting individual energy channels.

Spectrum Processing

• Peak separation using Gaussian deconvolution
• Automatic peak-overlap correction
• Automatic escape and sum peak removal
• Automatic Standardless Quantification using ZAF


Selecting Annotations from the Spectrum toolbar opens a new window that allows the user to measure, label, add text, etc. on the spectrum. These annotations are fully customizable and can be exported with the spectrum.

Spectrum Overlay

Spectra can be overlaid to easily compare the relative compositions in samples

Spectrum Reporting

Create a simple spreadsheet report of multiple spectra’s quantitative analysis.


  • Image Acquisition
  • Analysis Suite (Toolbar)
  • Morphology
  • Segmentation
  • Stitching/Montage
  • Automated Particle & Multi-point Analysi


The Direct Acquire tools allow for EDS data to be collected by selecting the region of interest from the SEM image. This includes spot/rectangle/free hand spectra as well as maps and linescans on the image.


Multipart Acquire allows fully automated spectrum analysis with customized EDS settings and automatically generated spectrum analysis reports. This includes single point, raster area, and freehand line spectrum acquisition.


Image Segmentation provides a visual representation of different phases in an image. Based upon histogram analysis, you can see the percent area each phase occupies.


Image Morphology provides particle information through image binarization. Image binarization transforms the image into grayscale based upon histogram data.
This allows you to label and measure pixels to provide an abundance of morphological data.


  • Multielement Linescan Acquisition
  • Linescan Overlay
  • DataView (Intensity/Concentration)
  • MultiScan
Iridium Ultra software


  • Mutielement Quantitative Mapping
  • Overlay Maps
  • Map Analysis Suite (Toolbar)
  • Extract Spectra (Freehand, Spot, Area)
  • Extract Linescan
  • DataView (Intensity/Concentration)
  • Beam Drift Correction
  • Maximum Pixel Spectrum
  • Map stitch & montage
  • Automate Stage and Beam automation
  • Composition Mapping
  • Phase Analysis


Selecting Annotations from the Map toolbar opens a new window that allows the user to measure, label, add text, etc. on the map.


Combine X-Ray Map pixels to extract spectra from a region of interest


Selecting Element Intensities from the Map tab will open a new window. A spot/rectangle/freehand can be placed on the image to compare the intensity/concentration.


Selecting Phase Maps from the Map tab will identify different phases within a sample and quantitatively analyze the elements within each phase.

The different phases will be graphically displayed in a map alongside phase-specific overlaid spectra to provide a qualitative comparison.


Analyze the element ratios in a region of interest and displays a comparison of element weight percent ratios.


Selecting Composition Mapping from the Map tab will identify map locations containing specific element concentrations according to specified parameters.

Quantitative analysis is performed on every pixel where a calculated concentration is compared to a specified concentration. Matching pixels are then displayed in the composition map.


Quantitative Maps convert the displayed pixel data to Concentration (wt%) from Intensity (cps).

This feature can display the quantitative maps as either elemental maps or components maps (ie; oxides).

Software screen


IXRF’s range of electronically cooled (LN free) Silicon Drift Detectors are optimized when coupled with an innovative ethernet-based digital pulse processor. IXRF SDD detectors provide exceptional and stable performance over a wide range of input count rates.





Energy Dispersive X-Ray Spectroscopy (EDS or EDX)

Energy Dispersive X-Ray Spectroscopy (EDS or EDX) is a chemical microanalysis technique used in conjunction with scanning electron microscopy (SEM). The EDS technique detects x-rays emitted from the sample during bombardment by an electron beam to characterize the elemental composition of the analyzed volume. Features or phases as small as 1 µm or less can be analyzed.

When a sample is bombarded by a SEM’s electron beam (top image), inner shell electrons may be ejected from atoms at the sample’s surface (center image). The energy of the SEM electron (e) beam must be greater than the energy with which the inner shell electron is bound to the nucleus of the atom. When an inner orbital electron is ejected from an atom, an electron from a higher energy level orbital will be transferred to the lower energy level orbital. During this transition a photon may be emitted from the atom. This fluorescent light (Kα) is the characteristic X-ray of the element (bottom image). The energy of the emitted photon will be equal to the difference in energies between the two orbitals occupied by the electron making the transition. Because the energy difference between two specific orbital shells, for a given element, is always the same (i.e. characteristic of that particular element), the photon emitted when an electron moves between these two levels will always have the same energy. Therefore, by determining the energy (keV) of the X-ray light (photon) emitted by a particular element, it is possible to determine the identity of that element.

For a particular energy (keV) of fluorescent light emitted by an element, the number of photons per unit time (generally referred to as peak intensity or count rate) is related to the amount of that analyte in a sample. The counting rates for all detectable elements within a sample are usually calculated by counting, for a set amount of time, the number of photons that are detected for the various analytes’ characteristic X-ray energy lines. Therefore, by determining the energy of the X-ray peaks in a sample’s spectrum, and by calculating the count rate of the various elemental peaks, it is possible to qualitatively establish the elemental composition and to quantitatively measure the concentration of those elements.

The EDS X-ray sensor measures the relative abundance of emitted X-rays versus their energy. Today sensors are typically Peltier-cooled, solid-state silicon drift detector (SDD) devices. When an incident X-ray strikes the detector, it creates a charge pulse that is proportional to the energy of the x-ray. The charge pulse is converted to a voltage pulse (which remains proportional to the x-ray energy) by a charge-sensitive pre-amplifier. The signal is then sent to a multichannel analyzer where the pulses are sorted by voltage. The energy, as determined from the voltage measurement, for each incident X-ray is sent to a computer for display and further data evaluation. The spectrum of x-ray energy versus counts is evaluated to determine the elemental composition of the sampled volume.

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