Electron probe microanalysis EPMA
In electron probe microanalysis, EPMA, high-energy electrons are focused onto the surface of the specimen. Due to the use of a thermal Schottky field emitter, the focusing extends into the nm range. The penetrating electrons interact with the atoms of the sample and characteristic X-rays are produced, which can be analyzed with wavelength- and energy-dispersive spectrometers.
ESMA provides quantitative chemical analysis in solids of all types at the micro- to nanometer scale. Analysis is performed on cross sections or surfaces. With detection limits > 10 ppm, ESMA covers all elements from Be to U and achieves relative accuracies in quantifying compositions of 1 to 5 percent. .
A particular strength is the sensitive analysis of light elements Be to F. The local carbon content can be measured quantitatively up to 500 ppm.
Applications
Solid materials:
- Application to all metallic and ceramic materials, semiconductors, composites, surface coatings/coatings, minerals, glasses.
- Determination of elemental distribution with line or area analysis, for example diffusion zones, depletions, segregations, partitioning, precipitations, surface treatments. Accurate chemical phase analysis. Oxidation, corrosion, etcetera.
Thin films:
- Determination of thickness , mass coverage, and composition of thin films in the thickness range 0.1nm < d < 1µm.
- Analysis of complex multilayers
Software for modeling X-ray emission of complex structures, for example particles, lamellae and multilayers. Inverse modeling is also possible.
Application examples from practice
Carbon partitioning in Dual Phase steels
Nitridation and decarburization of a Mn-rich steel
Cobald-Copper Oxides formed at reaction zones of Ag-14CuO and BSCF
The following is an overview of the available microscopes for EPMA at GFE.
Electron microprobe equipped with a Schottky field emission cathode JEOL JXA-8530F
built 2012
- Five wavelength dispersive spectrometers
- Multilayer crystals for soft X-ray detection
- Spectrometers for high intensities and fast mapping
- Two EDX systems with SDD technology from JEOL and Bruker
- Lateral resolution 3 nm at 30 kV, 40 nm at 10 kV 10 nA and 100 nm at 10 kV 100 nA
- Special equipment for light element analysis, especially for quantitative carbon analysis
Electron microprobe CAMEBAX SX 50
built 1991
- Four wavelength dispersive spectrometers
- Multilayer crystals for soft X-ray detection
Back to the "Services" overview