Fabrication and evaluation of highly c-plane oriented Mn3Sn thin films

MnxSn100-x thin films with different compositions (x=84, 80, 76, and 74) were fabricated on MgO (111) substrates by radiofrequency magnetron sputtering at room temperature and their properties were evaluated. The samples crystallized into Mn3Sn after thermal annealing at 400 degrees C or higher in vacuum. The Mn80Sn20 film showed only peaks of the (0001) family in out-of-plane XRD profiles, while the other films additionally showed other diffraction peaks indicating their polycrystalline structure. Cross-sectional transmission electron microscopy confirmed successful fabrication of highly c-plane orientated single-phased Mn3Sn thin film in the x=80 sample. The sample possessed a weak ferromagnetic component in the film plane, whose magnitude was comparable with that of bulk Mn3Sn. On the other hand, the out-of-plane magnetization curve had a linear response within +/- 5T. This magnetic anisotropy is the same as in bulk Mn3Sn. The Hall curve measured with electric current (magnetic field) along the [01 (1) over bar 10] ([0001]) axis indicated a negligibly small negative anomalous Hall effect (AHE). This response was also the same as in bulk Mn3Sn. We thus concluded that the anisotropies of the magnetic properties and AHE of Mn3Sn in a thin-film form are the same as those of bulk. (C) 2020 Author(s).