Triiron ditin intermetallic

The compound with empirical formula Fe3Sn2 is the first known kagome magnet. It is an intermetallic compound composed of iron (Fe) and tin (Sn), with alternating planes of Fe3Sn and Sn.

Preparation
The iron-tin intermetallic forms at around 750 C and naturally assumes a kagome structure. Quenching in an ice bath then cools the material to room temperature without disrupting the atomic structure.

Electronic structure
The compound's band structure exhibits a double Dirac cone, enabling Dirac fermions. A 30 meV gap separates the cones, which indicates the quantum Hall effect and massive Dirac fermions. Close measurement of the Fermi surface via the de Haas-van Alphen effect suggests that the massive fermions also exhibit Kane-Mele-type spin-orbit coupling.

Fe3Sn2 can also host magnetic skyrmions, but these typically require high magnetic fields to nucleate. For samples with a small (but nonzero) thickness gradient, only a small-amplitude (5-10 mT), direction-variant magnetic field suffices to nucleate the quasiparticles.