Observation of large intrinsic anomalous Hall conductivity in polycrystalline Mn₃Sn films

Topological antiferromagnets have a significant role to play in the modern day electronics and spintronics due to the presence of peculiar symmetries and magnetically driven large anomalous transport behaviour. We report the observation of anomalous Hall effect in Mn₃Sn polycrystalline thin films deposited on Al₂O₃ substrate with a large anomalous Hall conductivity of 65 (Ωcm)⁻¹ at 3 K. The Hall and magnetic measurements show a very small hysteresis owing to a weak ferromagnetic moment present in this material. The longitudinal resistivity decreases sufficiently for the thin films as compared to the polycrystalline bulk sample used as the target for the film deposition. The anomalous Hall resistivity and conductivity decreases almost linearly with the increase in the temperature. A negative magnetoresistance is observed for all the measured temperatures with the negative decrease in the magnitude with the increase in temperature.