Two-dimensional approach to fluorescence yield XANES measurement using a silicon drift detector

Area of Science:

• Materials Science
• Analytical Chemistry
• Spectroscopy

Background:

• Conventional partial fluorescence yield (PFY) methods for X-ray absorption near-edge structure (XANES) measurements can lose valuable X-ray fluorescence data.
• Distinguishing between elements with closely overlapping absorption edges in complex samples presents a significant analytical challenge.

Purpose of the Study:

• To introduce and demonstrate the capability of a novel two-dimensional (2D) approach to X-ray absorption near-edge structure (XANES) measurement.
• To showcase the advantages of the 2D-XANES technique in overcoming limitations of conventional PFY methods.

Main Methods:

• Implemented a two-dimensional (2D) X-ray absorption near-edge structure (XANES) measurement using a silicon drift detector as an energy-dispersive fluorescence detector.
• Applied the 2D-XANES mapping approach to analyze both diluted (Mn-doped nano-diamond) and concentrated (MnO crystal) manganese-containing samples.
• Utilized the technique for XANES measurements of SS304 stainless steel to detect trace phosphorus.

Main Results:

• The 2D-XANES approach successfully acquired full surveys of X-ray fluorescence data, unlike conventional PFY methods.
• The technique clearly differentiated the PFY spectra of manganese (Mn) and oxygen (O) atoms, even when their absorption edges are proximate.
• An unambiguous PFY spectrum of phosphorus (P) was extracted from the XANES measurement of SS304, detecting concentrations below 0.045 wt%.

Conclusions:

• The developed 2D-XANES method significantly enhances the analysis of complex materials by providing comprehensive fluorescence data.
• This advanced technique offers superior elemental discrimination, particularly for elements with overlapping absorption edges.
• The 2D-XANES approach proves effective for trace element detection and material characterization in diverse sample types.