EPMA technique, strengths & limitations
Electron microprobe analysis (EPMA) is an analytical technique that applies a focused beam of electrons on the sample surface. Through the interaction between the electrons and the sample, element-specific X-rays are produced, which are detected at particular wavelengths. Their intensities are measured to determine element concentrations in sample spots as small as 1-2 microns.
As a non-destructive analytical technique, EPMA makes it possible to use the same sample for further measurements as the bombardement with electrons does not lead to a loss of sample material.
- Major, minor and trace element concentrations (30 – 300 ppm, matrix-dependent, under special non-routine conditions) in minerals, glasses and other solid materials
- Wavelength-dispersive (WDS) and energy-dispersive (EDS) analysis of elements from carbon to uranium
- High-resolution imaging using secondary-electron, backscattered-electron, spectrally resolved cathodoluminescence, and WDS X-ray signals
- High spatial resolution achieved through a Schottky-type field-emission gun, resulting in a highly focused (30 – 50 nm) electron beam on the sample surface
- Quantitative analysis of features below 1 micron under low-kV conditions
- Liquids
- Highly volatile materials (the instrument operates under high vacuum: 1E-4 Pa)
- Organic materials (we can detect presence of carbon, but not quantitatively as these organics tend to volatilize under the beam). Carbon distribution mapping and qualitative analyses may be possible
JEOL’s field-emission gun EPMA (JXA-8530F Hyperprobe) at Utrecht University.
Read next about:
→ Technical specifications
→ Sample requirements & preparations
Go back to:
→ Facility access & services
→ National EPMA facility