Temperature-induced changes in the magnetism of Laves phase rare-earth--iron intermetallics by ab~initio calculations

TL;DR

This study uses ab initio calculations to investigate how temperature affects the magnetic properties of RFe2 Laves phase compounds, revealing a significant increase in the orbital to spin magnetic moment ratio with temperature.

Contribution

The paper provides the first ab initio analysis of temperature-dependent magnetic behavior in RFe2 compounds, highlighting the increase in m_orb/m_spin ratio with temperature.

Findings

The orbital to spin magnetic moment ratio increases with temperature.

The increase is significant and observable via x-ray magnetic circular dichroism.

The change is linked to reduced hybridization and increased atomic-like character.

Abstract

Laves RFe2 compounds, where R is a rare earth, exhibit technologically relevant properties associated with the interplay between their lattice geometry and magnetism. We apply ab~initio calculations to explore how magnetic properties of Fe in RFe2 systems vary with temperature. We found that the ratio between the orbital magnetic moment m_orb and the spin magnetic moment m_spin increases with increasing temperature for YFe2, GdFe2, TbFe2, DyFe2, and HoFe2. This increase is significant and it should be experimentally observable by means of x-ray magnetic circular dichroism. We conjecture that the predicted increase of the m_orb/m_spin ratio with temperature is linked to the reduction of hybridization between same-spin-channel states of atoms with fluctuating magnetic moments and to the associated increase of their atomic-like character.