Complex magnetism of lanthanide intermetallics unravelled

TL;DR

This paper uses advanced electronic structure theory to explain complex magnetic behaviors in gadolinium intermetallics, accurately predicting magnetic states, pressure effects on Curie temperature, and the impact of atomic substitutions.

Contribution

It introduces a comprehensive ab-initio approach that captures disordered local moments and strong f-electron correlations, providing new insights into magnetic interactions in lanthanide intermetallics.

Findings

GdZn and GdCd are simple ferromagnets.

Curie temperature increases with pressure, confirmed experimentally.

Atomic substitution alters magnetic order as predicted.

Abstract

We explain a profound complexity of magnetic interactions of some technologically relevant gadolinium intermetallics using an ab-initio electronic structure theory which includes disordered local moments and strong $f$-electron correlations. The theory correctly finds GdZn and GdCd to be simple ferromagnets and predicts a remarkably large increase of Curie temperature with pressure of +1.5 K kbar$^{-1}$ for GdCd confirmed by our experimental measurements of +1.6 K kbar$^{-1}$. Moreover we find the origin of a ferromagnetic-antiferromagnetic competition in GdMg manifested by non-collinear, canted magnetic order at low temperatures. Replacing 35\% of the Mg atoms with Zn removes this transition in excellent agreement with longstanding experimental data.