Scanning Electron Microscope-Energy Dispersive Spectrometry (SEM-EDS)
Overview
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Scanning Electron Microscope-Energy Dispersive Spectrometry (SEM-EDS) allows for qualitative to semi-quantitative chemical microanalysis of geological materials. SEM-EDS provides information on elemental composition, relative concentrations, and spatial distribution of elements at the microscale, supporting mineral identification, phase discrimination, and compositional characterization of complex materials.
Instrument Make & Model
Bruker ESPRIT Compact with XFlash 630M SDD
Estimated Measurement Time
- Sample Preparation: 5–45 mins/sample
- Sample Measurement: SEM-EDS measurement time varies depending on sample type and the level of analytical detail needed. Individual spot or object analyses may take only a few minutes, while more comprehensive analyses—such as multiple regions of interest, extended count times, or elemental mapping—may require several hours per sample.
Principles & Analytical Capabilities
Samples must be electrically conductive for SEM-EDS analysis. Non-conductive samples are typically coated with a thin conductive layer, most commonly carbon. Samples may be coated by the user prior to submission or prepared in our laboratory using the Leica EM ACE200 vacuum coater.
The Bruker EDS system supports multiple acquisition modes to characterize elemental composition and spatial variation:
Line Scan
Line scan analysis measures elemental variation continuously along a user-defined line across the sample surface. Elemental intensities are recorded as a function of distance, providing insight into compositional gradients, zoning, diffusion features, and phase boundaries. This mode is particularly useful for examining chemical transitions between mineral phases or across interfaces.
Object Scan (Point Analysis)
Object scan analysis provides rapid identification of elemental composition within a localized area or feature of interest, such as individual mineral grains, inclusions, or specific textures. Results include EDS spectra and calculated elemental concentrations, supporting phase identification and comparative compositional analysis.
Mapping Scan
Elemental mapping enables visualization of elemental distributions over a defined area of the sample. X-ray data are collected at each pixel to generate two-dimensional elemental maps, revealing compositional heterogeneity, mineral associations, and textural relationships. Elemental maps can be correlated with SEM images to link chemistry with morphology.
Data Generated
Data components:
- Netto – Net Counts
- Mass [%]
- Mass Norm. [%]
- Atom [%]
- Sto. [%]
- Sto. Norm. [%]
- Abs. Error [%]
- Rel. Error [%]
Image files:
- JPG: scanning electron microscope (available as PNG, BMP, or TIFF upon request)
Data files:
- Results (DOCX): Exported version of the ESPRIT Compact standard Report (images, text tables, graphs)
- Results (XLSX): Exported version of the ESPRIT Compact standard Report (tabular data)
Raw files:
- Metadata file (TXT): instrument settings and image metadata
- Mapping (BCF): EDS analysis mapping mode file
- Line Scan (RTL): EDS analysis line scan mode file
- Object Scan (RTO): EDS analysis line scan mode file
- Spectra (SPX): EDS analysis spectra for each mode file
- EDS Report (RPT): ESPRIT Compact standard report
Data Example
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Procedures & Manuals
References
1 St. John, K.E.K., Lucchi, R.G., Ronge, T.A., Barcena, M.A., De Schepper, S., Duxbury, L.C., Gebhardt, A.C., Gonzalez-Lanchas, A., Goss, G., Greco, N.M., Gruetzner, J., Haygood, L., Husum, K., Iizuka, M., Kapuge, A.K.I.U., Lam, A.R., Libman-Roshal, O., Liu, Y., Monito, L.R., Reilly, B.T., Rosenthal, Y., Sakai, Y., Sijinkumar, A.V., Suganuma, Y., and Zhong, Y., 2026. Site U1619. In Lucchi, R.G., St. John, K.E.K., Ronge, T.A., and the Expedition 403 Scientists, Eastern Fram Strait Paleo-Archive. Proceedings of the International Ocean Discovery Program, 403: College Station, TX (International Ocean Discovery Program). https://doi.org/10.14379/iodp.proc.403.104.2026