Ab initio approach of the hydrogen insertion effects on the magnetic properties of $ {\bf ScFe_2} $

TL;DR

This study uses density functional theory to analyze how hydrogen insertion affects the electronic and magnetic properties of ScFe2 and its dihydride, revealing changes in magnetization and hyperfine fields.

Contribution

It provides a detailed ab initio analysis of hydrogen's effects on magnetic properties, highlighting the roles of hydrogen bonding and cell expansion.

Findings

Hydrogen insertion enhances magnetization in ScFe2.

Fermi contact hyperfine fields invert order upon hydriding.

Chemical bonding analysis explains magnetization changes.

Abstract

The electronic and magnetic structures of $ {\rm ScFe_2} $ and of its dihydride $ {\rm ScFe_2H_2} $ are self-consistently calculated within the density functional theory (DFT) using the all electron augmented spherical wave (ASW) method with the local spin density approximation (LSDA) for treating effects of exchange and correlation. The results of the enhancement of the magnetization upon hydrogen insertion are assessed within an analysis of the chemical bonding properties from which we suggest that both hydrogen bond with iron and cell expansion effects play a role in the change of the magnitude of magnetization. In agreement with average experimental findings for both the intermetallic system and its dihydride, the calculated Fermi contact terms $H_{FC}$ of the $^{57}$Fe M\"ossbauer spectroscopy for hyperfine field, at the two iron sites, exhibit an original inversion for the order of magnitudes upon hydriding.