Antiferromagnetic ordering in spinel GeV₄Se₈

In the search for topologically non-trivial spin textures, the spinel family of materials stands out as a host of such phenomena. Lacunar spinels (AM4X8) are a subset of spinels, where there is an ordered vacancy on the A-site, which results a breathing pyrochlore structure.  In these compounds, there are two major molecular units, namely, (AX4)n- cubane, and (M4X4)n+ tetrahedral units. Because of those weakly coupled molecular units, lacunar spinels demonstrate exotic behavior, where some members host a Néel-type skyrmion lattice. We have synthesized powder samples of GeV4Se8. The physical properties were investigated with x-ray diffraction, magnetometry, and neutron diffraction measurements. The room temperature x-ray diffraction data confirm that GeV4Se8 crystallizes in the space group 216 (F-43m). The magnetometry data shows anomalies 12, and 34 K. The neutron diffraction data shows that the 12 K transition corresponds to the onset of long-range antiferromagnetic order in GeV4Se8.