Magnetic Order of Dresselhaus-type Antiferromagnet EuIr${}_4$In${}_2$Ge${}_4$ Studied by Single Crystal Neutron Diffraction

The magnetic order of EuIr${}_4$In${}_2$Ge${}_4$, which crystallizes in a Dresselhaus-type noncentrosymmetric tetragonal structure, was investigated using two complementary single-crystal neutron diffraction approaches. Time-of-flight single-crystal diffraction reveals antiferromagnetic Bragg reflections with propagation vector $q=(1,0,0)$ below the Néel temperature $T_{\mathrm{N}}$ = 2.5 K, indicating a breaking of body-centered translational symmetry. Polarized neutron diffraction on a triple-axis spectrometer demonstrates that the ordered Eu${}^{2+}$ $4f$ moments lie within the basal plane and form a collinear antiferromagnetic structure with antiparallel alignment between corner and body-center sites. Despite the Dresselhaus-type spin splitting in the conduction bands, the magnetic order remains simple, implying weak coupling between localized moments and itinerant electrons.