Structural, magnetic, and electron-transport properties of epitaxial Mn₂PtSn films

The growth of new magnetic materials on suitable insulating substrates is an important part of the development of spin-electronics devices for memory or information processing. Epitaxial thin films of Mn₂PtSn were grown on a MgO [001] substrate by magnetron co-sputtering of the constituents. Structural, magnetic, and electron-transport properties were investigated. The epitaxial Mn₂PtSn film has an inverse tetragonal structure with the c-axis aligned in the plane of the MgO substrate. The lattice constants determined using XRD and TEM analysis are c = 6.124 Å and a = b = 4.505 Å. The orientation of Mn₂PtSn c-axis which is 45° away from the a-axis of MgO has resulted in a small lattice mismatch of about 2.8%. The measured saturation magnetization is 5.3 μ_B/f.u., which is smaller than the first-principles calculated value of 6.4 μ_B/f.u. for ferromagnetic spin arrangement. Magnetization measurements determined the bulk magnetocrystalline anisotropy constant K_v of about 11.3 Merg/cm³ (1.13 MJ/m³). The electron-transport behavior is similar to that of normal magnetic metals. These results indicate that Mn₂PtSn may have promising applications in spintronic devices.