An Effective Method to Estimate Composition Amplitude of Spinodal Decomposition for Atom Probe Tomography Validated by Phase Field Simulations

TL;DR

This paper introduces a new method using amplitude density spectrum to accurately estimate composition amplitude in early-stage spinodal decomposition from atom probe tomography data, bridging experimental and simulation techniques.

Contribution

The paper presents an effective amplitude estimation method that improves early-stage spinodal decomposition analysis and addresses limitations of existing methods.

Findings

The new method sensitively detects early-stage composition amplitudes.

It reveals that the Langer-Bar-on-Miller method underestimates amplitudes.

Case studies on Fe-Cr alloys validate the approach.

Abstract

Reasonable evaluation of composition amplitude in spinodal decomposition is a challenge to microanalysis of atom probe tomography, especially at early stages when phase separation is not prominent. This impedes quantitative analysis of spinodal structure in atom probe tomography as well as comparison with simulated results from phase field simulations. We hereby report an effective method to estimate the composition amplitude by constructing an amplitude density spectrum. This method can sensitively determine the composition amplitude at early stages. In particular, it substantially bridges experimental and simulation techniques comprising both discrete and continuum data in the study of spinodal decomposition. Moreover, it was found that the commonly adopted Langer-Bar-on-Miller method for atom probe analysis underestimates the composition amplitude of spinodal decomposition. Case studies have been performed on the Fe-Cr binary alloys.