Morphology and Magneto-Transport Properties of Submicron Grains of the Topological Antiferromagnet Mn₃Sn

The topological antiferromagnet Mn₃Sn [0] exhibits ferromagnetic-like responses such as the Anomalous Hall and Nernst Effects (AHE/ANE) due to its time-reversal symmetry breaking magnetic structure [1,2]. Recently, Mn₃Sn thin films have been of interest due to their role in spintronics [3,4], and studies of submicron Mn₃Sn particles could expand the material’s use in nanotechnology. In this work, Mn₃Sn films with varying thickness t were fabricated by DC magnetron sputtering on Si/SiO₂ substrates at crystallization temperature. Through atomic force microscopy (AFM) measurements, our films were seen to be amalgamations of submicron formations. When t ≦ 20 nm, individual isolated grains made up the films. Depending on t, the sizes of these grains vary from tens to hundreds of nanometers. AHE was observed in the Mn₃Sn grains covered by a conducting layer, suggesting that our grains possess finite Berry curvature in momentum space, which could further cement the material’s role in spintronics.