Epitaxial growth of Kagome semimetal FeSn and Mn₃Ge

The Kagome lattice is hexagonal and composed of corner sharing triangles. Materials with layered Kagome lattice allow the interplay of topological properties and interactions in flat bands, and can give rise to spin liquids, skyrmions and other novel phases. There is broad interest in realizing high-quality topological semimetal materials such as Mn₃X (Sn, Ge and others) [1], FeSn [2] and Co₃Sn₂S₂ [3], in layered Kagome structure. Both angle-resolved photoemission spectroscopy (ARPES) and transport measurement indicate they are topologically nontrivial. Until now, most measurements are performed on bulk samples which can be a limitation for both physics and application. By using molecular beam epitaxy and sputtering, We synthesized Kagome structured FeSn and Mn₃Ge films. Both in-situ and ex-situ characterizations indicate these films are highly crystalline and c-axis oriented. Highly ordered atomic layers are captured by scanning transmission electron microscopy. Anomalous Nernst effect has been measured which can be related to non-vanishing Berry curvature.