G-type antiferromagnetic structure in the metallic d-wave altermagnet Rb_1-δV₂Te₂O

Altermagnetism, known for its non-relativistic spin-split band structures with yet compensated moments, is being intensively investigated. Discovering new altermagnetic materials with characteristics suitable for practical use remains an important ongoing task. Recently, a metallic room-temperature altermagnet candidate Rb_1-\deltaV_2Te_2O with a layered structure and d-wave spin symmetry has been reported based on experimental results from spin-resolved photoemission spectroscopy and scanning tunnelling microscopy/spectroscopy measurements. Here we report neutron powder diffraction investigations on the magnetic structure of Rb_1-\deltaV_2Te_2O, which show a G-type antiferromagnetic structure below the transition temperature of 337 K. The result is different from the original theoretical expectation, which might lead to new insights on the physics of this altermagnet candidate.