Large room temperature anomalous Hall effect in c axis oriented non-collinear antiferromagnetic Mn3Ga thin films with ferrimagnetic Mn3Ga inclusion

Non-collinear antiferromagnets Mn3X (X = Sn, Ge, Ga) have recently attracted a lot of attention due to their fascinating properties with great application prospects in spintronics. Mn3Ga possesses the highest Néel temperature among this family, providing huge potential for realistic spintronic device application. However, the small anomalous Hall conductivity of Mn3Ga makes it lack competitiveness. In this paper, c axis oriented Mn3Ga thin films with D019 hexagonal structure were prepared by optimizing the MgO(111) substrate temperature. Large anomalous Hall resistivity up to 1.53 μΩ cm at 300 K is observed for (0002) oriented Mn3Ga film grown at 450 °C, corresponding to a Hall conductivity of about 30 Ω−1 cm−1. Further analysis indicates that the skew-scattering mechanism, which is attributable to the presence of a small amount of the D022-Mn3Ga phase, is the main source for the large Hall conductivity observed here. These results raise the intriguing prospect of Mn3Ga films as a key component in antiferromagnetic spintronic devices.