Destabilization of the Mg-H system through elastic constraints

TL;DR

This study demonstrates how elastic constraints can significantly alter the thermodynamics of hydrogen absorption in magnesium, leading to improved hydrogen storage properties.

Contribution

The paper introduces an elastic model to explain how elastic clamping affects hydrogen absorption thermodynamics in Mg films with alloy-forming elements.

Findings

Mg films with Pd/Ni show much higher hydrogen plateau pressures than bulk Mg.

Elastic constraints influence the hydrogen absorption thermodynamics.

The model explains the Mg thickness dependence of hydrogen pressure.

Abstract

We tune the thermodynamics of hydrogen absorption in Mg by means of elastic clamping. The loading isotherms measured by hydrogenography show that Mg films covered with Mg-alloy-forming elements, such as Pd and Ni, have hydrogen plateau pressures more than two orders of magnitude higher than bulk Mg at the same temperature. An elastic model allows us to interpret the Mg thickness dependence of the hydrogen plateau pressure. Our results provide the basis for the development of new hydrogen storage materials with excellent thermodynamic properties.