Single-Ion Deconvolution of Mass Peak Overlaps for Atom Probe Microscopy

Area of Science:

• Materials Science
• Analytical Chemistry
• Surface Science

Background:

• Atom probe tomography (APT) is a powerful technique for 3D material characterization.
• Mass spectra in APT often exhibit overlapping peaks due to intrinsic evaporation, limited mass resolution, and unknown ion kinetic energies.
• This peak overlap leads to significant inaccuracies in quantitative composition measurements.

Purpose of the Study:

• To develop a novel methodology for resolving overlapping peaks in atom probe mass spectra on an ion-by-ion basis.
• To enable accurate, spatially resolved compositional analysis in complex material microstructures.
• To provide a deconvolution technique compatible with existing point cloud analysis tools.

Main Methods:

• A new ion-by-ion deconvolution approach is presented, analyzing the isotopic abundance of ions in their immediate spatial vicinity.
• This method resolves the identity of individual ions previously obscured by peak overlap.
• The technique is validated through two detailed case studies on complex material systems.

Main Results:

• The proposed ion-by-ion method successfully deconvolutes overlapping peaks in atom probe mass spectra.
• Accurate, spatially resolved compositional data is obtained, overcoming limitations of previous global or region-based deconvolution methods.
• The resulting deconvolution yields a point cloud amenable to standard APT data analysis workflows.

Conclusions:

• The ion-by-ion deconvolution technique offers a significant advancement for accurate quantitative analysis in atom probe tomography.
• This method enhances the reliability of compositional measurements, particularly across material interfaces and within clusters.
• Future work should focus on further refining the technique and exploring its limitations in diverse material applications.