Large anomalous Hall and Nernst effects in the ferromagnetic semimetal candidate Mn3Sn2

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Recent theoretical calculations have shown that Mn₃Sn₂, a well-known magnetocaloric material with multiple magnetic transitions, possesses both nodal lines and nodal surfaces in its electronic structures, making it an excellent platform for studying anomalous transport properties in magnetic topological candidates. In this work, we performed comprehensive electrical, thermal, and thermoelectric measurements on Mn₃Sn₂ single crystals. The electrical resistivity ρ(T) shows an abnormal peak near the Curie temperature, TC2~227 K, and a negative resistivity slope above TC2, which are probably related to a large spin-fluctuation scattering. The Seebeck coefficient Sₓₓ(T) shows a sign reversal below 80 K although the Hall coefficient is always positive, which might be ascribed to the magnon-drag effect. Below TC1~262 K, a significant anomalous Hall effect is observed, and the anomalous Hall resistance (ρxyA) peaks at around 7 {}{Ω} cm at 200 K. ρxyA exhibits a quadratic dependence on the longitudinal resistivity ρₓₓ, and the anomalous Hall conductivity σxyA remains nearly temperature independent below 200 K, suggesting the dominance of the intrinsic Berry-phase mechanism. Correspondingly, we also detect a large anomalous Nernst effect, with the anomalous Nernst coefficient reaching approximately 10.16em0exμV0.16em0exK^-1 at 200 K. Despite Mn₃Sn₂ exhibiting robust ferromagnetism, its anomalous Hall angle (2.5%), anomalous Nernst angle (6.5%), and large anomalous Nernst coefficient $(1.65{{4pt}{0ex}}{{0.16em}{0ex}}{μ}V{{0.16em}{0ex}}{K}^{{-}1}{{0.16em}{0ex}}{T}^{{-}1})$ surpass those observed in typical ferromagnetic materials. Our results experimentally demonstrate the existence of topologically nontrivial states in ${Mn}₃{Sn}₂$.