Spatially resolved 3D micro-XANES by a confocal detection scheme.

Area of Science:

• Materials Science
• Geoscience
• Spectroscopy

Background:

• Micro X-ray absorption near edge structure (mu-XANES) spectroscopy is crucial for analyzing elemental composition and chemical states at micro-scales.
• Achieving high spatial resolution in fluorescence detection mode for mu-XANES has been a significant challenge.
• Previous methods lacked the necessary three-dimensional (3D) resolution for detailed microstructural analysis.

Purpose of the Study:

• To demonstrate a novel confocal setup for 3D spatially resolved mu-XANES.
• To apply this technique for the investigation of mineral inclusions in natural diamonds.
• To achieve precise microstructural characterization at the micro-scale.

Main Methods:

• Utilized a confocal setup incorporating polycapillary half-lenses for beam focusing and detection.
• Employed a fluorescence detection mode at the DUBBLE XAS station (ESRF BM26A).
• Characterized the detection volume, achieving full-width-half-maxima of 18.5 x 12.0 x 10.0 micrometers cubed at the Cu K-edge.

Main Results:

• Successfully demonstrated 3D spatially resolved mu-XANES using the developed confocal setup.
• The confocal micro-XANES mode provided a well-defined ellipsoidal detection volume.
• Applied the technique to study mineral inclusions in natural diamonds at the Fe K-edge.

Conclusions:

• The developed confocal setup enables high-resolution 3D spatially resolved mu-XANES.
• This technique is effective for analyzing microstructural features, such as mineral inclusions in diamonds.
• The method offers a powerful tool for advanced materials and geoscience research.