Blind deconvolution of time-of-flight mass spectra from atom probe tomography

Area of Science:

• Materials Science
• Analytical Chemistry
• Spectroscopy

Background:

• Compositional measurements in atom probe tomography (APT) are limited by uncertainties in mass spectral peak assignment.
• Peak overlap and broadening in experimental mass spectra hinder accurate identification of ion species.

Purpose of the Study:

• To develop a novel method for deconvoluting experimental APT mass spectra.
• To accurately determine peak intensities and shapes, correcting for field evaporation and detection processes.

Main Methods:

• A linear and time-invariant model was developed to describe peak shapes and intensities.
• The model was fitted to experimental data by minimizing squared residuals, regularized with the maximum entropy method.
• The method was validated using synthetic data and applied to Fe-Cr APT data.

Main Results:

• The method successfully deconvoluted experimental mass spectra into ideal spectra and system functions.
• Peak intensities were recovered to within ±0.33 at% for synthetic data.
• The approach demonstrated potential for improved compositional determination and error estimation in APT.

Conclusions:

• The developed deconvolution method significantly enhances the accuracy of compositional measurements in APT.
• Understanding peak shapes provides new avenues for error analysis, including peak overlap and isotope abundance constraints.
• This technique offers a pathway to more reliable and precise quantitative analysis in materials science.