Determining symmetry and crystal structure of kagome bilayer compound Fe3Sn2

We propose high-resolution x-ray diffraction on the topological kagome metal Fe3Sn2. This trigonal compound exhibits ferromagnetic order below 650 K and undergoes a spin reorientation toward the ab-plane below 200 K. At low temperatures, magnetic order and orbital nematicity violate three-fold symmetry and creates preconditions for the symmetry lowering of the crystal structure that we seek to probe in the high-resolution experiment. By temperature-dependent diffraction studies, we will address the origin of the spin reorientation in Fe3Sn2 and gauge changes in the crystal structure that affect its topological energy bands. This will be an essential step to quantify magnetoelastic coupling in the family of Fe-Sn kagome metals.