Bridging the micro-to-macro gap: a new application for micro X-ray fluorescence

Area of Science:

• Materials Science
• Analytical Chemistry
• Geochemistry

Background:

• X-ray elemental mapping and X-ray spectrum imaging are valuable microanalytical techniques.
• Spatial limitations of scanning electron microscopes and microprobes restrict analysis to small sample areas.
• Analyzing large, heterogeneous materials like concrete requires methods capable of macro-scale examination.

Purpose of the Study:

• To address the limitations of microbeam analysis for large-area elemental mapping.
• To introduce and evaluate Micro X-ray fluorescence-X-ray spectrum imaging (μXRF-XSI) as a solution for macro-scale analysis.
• To demonstrate the advantages of μXRF-XSI over electron-excitation sources for heterogeneous materials.

Main Methods:

• Utilized Micro X-ray fluorescence-X-ray spectrum imaging (μXRF-XSI) with an X-ray excitation source.
• Employed a mid-sized beam for analysis, enabling operation at atmospheric pressure.
• Compared μXRF-XSI capabilities with traditional electron microbeam methods.

Main Results:

• μXRF-XSI overcomes the spatial limitations of electron microprobes for analyzing large specimens (>10 cm²).
• The technique allows for macro-scale imaging of heterogeneous materials, revealing structures and concentration gradients.
• μXRF-XSI offers lower limits of detection due to the absence of electron-induced bremsstrahlung and can complement electron microbeam analysis.

Conclusions:

• μXRF-XSI is a powerful tool for the macro-scale elemental analysis of large and heterogeneous samples.
• This method provides a viable alternative to microbeam techniques when large area coverage is required.
• μXRF-XSI enhances analytical capabilities by complementing finer-scale microanalysis and offering improved detection limits.