Quantification challenges for atom probe tomography of hydrogen and deuterium in Zircaloy-4

TL;DR

This paper discusses the difficulties in accurately quantifying hydrogen and deuterium in Zircaloy-4 using atom probe tomography, highlighting peak overlap issues and proposing methods for better analysis in nuclear materials.

Contribution

It identifies specific challenges in quantifying hydrogen isotopes in zirconium alloys via APT and suggests strategies to improve data interpretation.

Findings

Peak overlap complicates hydrogen/deuterium quantification

Electrochemical charging creates large hydrides and deuterides

Strategies are discussed to improve APT analysis accuracy

Abstract

Analysis and understanding of the role of hydrogen in metals is a significant challenge for the future of materials science, and this is a clear objective of recent work in the atom probe tomography (APT) community. Isotopic marking by deuteration has often been proposed as the preferred route to enable quantification of hydrogen by APT. Zircaloy-4 was charged electrochemically with hydrogen and deuterium under the same conditions to form large hydrides and deuterides. Our results from a Zr hydride and a Zr deuteride highlight challenges associated to accurate quantification of hydrogen and deuterium, in particular associated to the overlap of peaks at low mass-to-charge ratio and of hydrogen/deuterium containing molecular ions. We discuss possible ways to ensure that appropriate information is extracted from APT analysis of hydrogen in a zirconium alloy systems that is important for nuclear power.