Magnetic and transport properties in antiferromagnetic antiperovskite Eu3SnO

Magnetic Dirac electron systems have attracted intense research interest for their unique magnetoelectric properties. Here, we report the magnetic and transport properties of the antiperovskite ${\mathrm{Eu}}_{3}\mathrm{SnO}$, which was identified as a topological semimetal characteristic by first-principles theoretical calculations [A. Pertsova et al., Phys. Rev. B 99, 205126 (2019)]. A metastable canted antiferromagnetic state between the paramagnetic and the ferromagnetic phases was observed in ${\mathrm{Eu}}_{3}\mathrm{SnO}$. Further, the magnetoresistance and Hall resistance show the anomalies below the N\'eel temperature. On the corresponding magnetic phase transition point, the transport properties undergo sharp drops which verify the characteristics of magnetic properties. Meanwhile, we found the coexistence of ${\mathrm{Eu}}^{2+}$ and ${\mathrm{Eu}}^{3+}$ in ${\mathrm{Eu}}_{3}\mathrm{SnO}$ by analyzing experimental and theoretical data, which indicate the localized-itinerant dual properties of the $f$-orbital electrons. Finally, we plot the phase diagram for ${\mathrm{Eu}}_{3}\mathrm{SnO}$ by collecting the inflection/maximum points of the magnetization, heat capacity, and magnetoresistance/Hall-resistance curves. The phase diagram shows four magnetic-ordered regions including antiferromagnetic phase I, ferrimagnetic phases II and III, and ferromagnetic-like phase IV. This study opens up possibilities for the investigation of fascinating properties in such theoretically predicted antiferromagnetic topological semimetals.