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

Abstract

Rare-earth ($R$) half-Heusler compounds $R$BiPt exhibit a wide spectrum of interesting ground states. 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 $[111]$ direction, satisfying one of the requirements for an antiferromagnetic topological insulator as proposed previously, where both time-reversal symmetry and lattice translational symmetry are broken, but their product is conserved.