• Models SXFive FE Electron Probe MicroAnalyser and SX100 Electron Probe MicroAnalyser from CAMECA , each with energy dispersive (EDS) and wavelength dispersive X-ray spectroscopy (WDS)
• including equipment for recording SE and BSE images
• Highly spatially resolved geochemical analysis of element concentrations in solids
• Results are usually given for each measuring point in wt.% of oxides

Contact person

• Dietlind Nordhausen
• Dr. Thomas Schirmer

configuration

CAMECA SXFive FE:

Evaluation:

• MinIdent (Prof. Dorian G.W. Smith & David Peirre Leibovitz; mineral identification)

applications

• Qualitative and quantitative element analysis (minerals, rocks, technical products)
• Applicable for thin sections and polished sections
• Analysis depending on application and matrix topography/element mapping (minerals, rocks, technical products)
• Extensive range of international reference materials for calibration of most applications in the field of geology and materials science

Energy dispersive X-ray spectroscopy (EDS)

• EDS is used for the rapid qualitative identification of all minerals or components contained in the sample and the subsequent selection of measuring points for WDS
• well suited for the determination and differentiation of accessory minerals (zircon, apatite, rutile, etc.)
• only suitable for quantitative analyses to a limited extent, as the detection limit for most elements is 0.1% by weight at best
• measurement inaccuracies and unresolvable line interferences possible
• excited atoms emit X-rays with an energy specific to the respective element (characteristic radiation)
• Detector measures the energy of each incoming X-ray photon

Wavelength dispersive X-ray spectroscopy (WDS)

• WDS requires significantly longer measurement times, but provides much more accurate measurement results and has a detection limit of around 100 ppm.
• Decomposition of X-rays into their spectral components by diffraction from natural or synthetic crystals
• Characteristic X-rays of an element are analyzed
• The different wavelength ranges are scanned one after the other for a complete spectrum

BSE images

• Acquisition of high-resolution BSE images by detecting backscattered electrons on the sample surface
• Material contrast images provide a grayscale image that can be used to identify individual minerals according to their different mean atomic numbers and to visualize the microstructures

Preparation of thin sections

• Bal-Tec MED 020 (coating with C, Ag, Au etc.)
• Vaporization of uncovered thin sections with a carbon layer a few nanometers thick to prevent negative charging of the sample
• Electrons are conducted away from the sample surface during the analysis via a carbon strip that connects the thin section to the stainless steel sample carrier