The effect of hydrogen on the magnetic properties of FeV superlattice

TL;DR

This study investigates how hydrogen incorporation affects the electronic and magnetic properties of a FeV superlattice, revealing that hydrogen location influences magnetic moments and that hydrogenation can increase magnetic moments, driven by volume changes.

Contribution

It is the first to report an increase in magnetic moments due to hydrogenation in FeV superlattices, emphasizing volume effects over electronic interactions.

Findings

Hydrogen prefers interior vanadium sites energetically.

Magnetic moments increase as hydrogen moves toward Fe-V interface.

Magnetic moment initially decreases then increases with hydrogen filling.

Abstract

The electronic and magnetic structures of a hydrogenated and hydrogen free superlattice of 3 iron monolayers and 9 vanadium monolayers are studied using the first principle full-potential augmented-plane-wave method as implemented in WIEN2k package. The volume, the total energy and the magnetic moments of the system are studied versus the hydrogen positions at the octahedral sites within the superlattice and also versus the filling of the vanadium octahedral location by hydrogen atoms. It is found that the hydrogen locations at the interior of vanadium layer are energetically more favourable. The local Fe magnetic moment and the average magnetic moment per supercell are found to increase as the H position moves towards the Fe-V interface. On the other hand, the average magnetic moment per supercell is found to initially decrease up to filling by 3 H atoms and then increases afterwards. To our knowledge, this is the first reporting on the increase in the computed magnetic moment with hydrogenation. These trends of magnetic moments are attributed to the volume changes resulting from hydrogenation and not to electronic hydrogen-metal interaction.