Hydrogen dynamics in high entropy alloy Ti0.8Zr1.2CrMnFe1+XNi1-X (X=0, 0.25, 0.5, 0.75 and 1) using Inelastic Neutron Scattering (TOSCA)

High entropy alloys (HEA) are a new class of alloy, which are made up of at least five elements, each one of them having an abundance between 5 and 35 at.%. In these alloys, the entropy term dominates and produces a structure that is usually BCC or FCC. Recently, these alloys have been investigated for their hydrogen storage properties. However, we still need fundamental understanding of the change of hydrogen storage characteristics when elements are substituted. Recently, we found that the HEA of composition Ti0.8Zr1.2CrMnFe1+xNi1-x with x = 0, 0.25, 0.5, 0.75 and 1 have good hydrogen storage properties. It could store 1.4 wt.% of hydrogen between 1 and 10 bars of hydrogen at room temperature which makes it interesting for fuel cells applications. Substitution of Fe by Ni slightly change the thermodynamic of the hydrogenation but, as Ti and Fe have the same atomic radius the reason is more likely due to different valence. This will have an impact on the dynamic of hydrogen in its interstitial site. We are planning to measure the inelastic scattering of these alloys in the fully hydride and dehydrided state in order to better understand the hydrogen dynamics in HEA.