Magnetic order in GdBiPt studied by x-ray resonant magnetic scattering

TL;DR

This study uses x-ray resonant magnetic scattering to investigate the magnetic structure of GdBiPt, revealing antiferromagnetic order consistent with properties of an antiferromagnetic topological insulator, advancing understanding of its quantum state.

Contribution

First detailed microscopic characterization of GdBiPt's magnetic structure confirming its potential as an antiferromagnetic topological insulator.

Findings

Gd moments order antiferromagnetically below 8.5 K

Magnetic stacking occurs along the cubic diagonal [1 1 1]

Order satisfies conditions for an antiferromagnetic topological insulator

Abstract

Rare earth (R) half-Heusler compounds, RBiPt, exhibit a wide spectrum of novel ground states. Recently, GdBiPt has been proposed as a potential antiferromagnetic topological insulator (AFTI). We have employed x-ray resonant magnetic scattering to elucidate the microscopic details of the magnetic structure in GdBiPt below T_N = 8.5 K. Experiments at the Gd L_2 absorption edge show that the Gd moments order in an antiferromagnetic stacking along the cubic diagonal [1 1 1] direction satisfying the requirement for an AFTI, where both time-reversal symmetry and lattice translational symmetry are broken, but their product is conserved.