Surface oxide on thin films of yttrium hydride studied by neutron reflectometry

TL;DR

This study demonstrates the use of neutron reflectometry to analyze surface oxide layers on yttrium hydride thin films, providing detailed insights into oxide thickness and oxygen penetration, which are difficult to obtain with standard methods.

Contribution

It introduces neutron reflectometry as an effective tool for analyzing H-containing thin films, specifically revealing oxide characteristics on yttrium hydride surfaces.

Findings

Surface oxide layer of 5-10 nm thickness identified

Neutron reflectometry provides strong contrast for H-containing films

Method enables non-destructive analysis of surface oxidation

Abstract

The applicability of standard methods for compositional analysis is limited for H-containing films. Neutron reflectometry is a powerful, non-destructive method that is especially suitable for these systems due to the large negative scattering length of H. In this work we demonstrate how neutron reflectometry can be used to investigate thin films of yttrium hydride. Neutron reflectometry gives a strong contrast between the film and the surface oxide layer, enabling us to estimate the oxide thickness and oxygen penetration depths. A surface oxide layer of 5-10 nm thickness was found for unprotected yttrium hydride films.