SEM EDS

Energy Dispersive X-Ray Spectroscopy (SEM-EDS) Services

Energy Dispersive X-ray Spectroscopy (known as EDS, EDX, EDXS) can be coupled with SEM to analyze the chemical makeup of a sample.

EDS relies on the principle of x-ray fluorescence, which is produced by one type of interactions between the applied electron beam and the sample surface. When inelastic interactions occur, an x-ray photon is excited and emit from the sample with an energy characteristic of the species of the atom that produced it. Specialized detectors collect these photons as the applied electron beam is scanned over the sample, to yield chemical information on a pixel-by-pixel basis. The surface of the sample can be thus be scanned with resolution nearly comparable to that of SEM (not quite as high) to produce a semi-quantitative compositional spectrum.

SEM-EDS Measurements:

  • Elemental composition determination at specific points or areas on the sample
  • Mapping of elemental distribution within a sample: in 1, 2, or 3 dimensions
  • Phase analysis of multimodal materials

Uses & Limitations of SEM-EDS

  • What it’s great for:
    • Identification of elements present within 2-5 um of the sample surface
    • Semi-quantitative chemical composition analysis, including composition mapping and profiling
  • Limitations:
    • EDS does not always yield highly accurate metrics of chemical composition

Example Output of SEM-EDS:

EDS Scan of alloy material used in connector pin of defective terminal block plug. Scanned to determine chemical change associated with device failure.

20kX Magnified SEM image of an area on a connector pin scanned for EDS analysis.

Instruments we use for SEM-EDS:

Nearly all our SEM instruments are outfitted with an EDS detection system:

FEI Helios 600i uses an Oxford 80mm SDD EDS detector

FEI Quanta 200 uses a Thermo Fisher Scientific high-speed 30mm SDD EDS detector

Hitachi 4700 uses an EDAX EDS detector

Zeiss Ultra-55 uses an Oxford 10mm SDD EDS detector

Thermo Fisher Scientific PFIB G4 UXe uses Thermo Fisher’s Pathfinder 100mm SDD EDS detector