Tunable Phase of Mn₂Ga Films on Cr Buffer Layer

摘要

Thin Mn₂Ga films were grown on MgO substrates with different thicknesses of Cr buffer layer using the molecular beam epitaxy technique. The cubic half-Heusler C1b structure is obtained when the thickness of Cr buffer layer is below 3 nm. The phase is proven to show soft ferrimagnetism with a saturation magnetization Ms of 280 emu/cc. Tetragonal hard ferrimagnetic Mn₂Ga in D0₂₂structure with high-perpendicular magnetic anisotropy is obtained when increasing the thickness of Cr buffer above 3 nm. Different phases of Mn₂Ga films with various thicknesses of Cr buffer can be attributed to the tensile strain and the Cr-Mn₂Ga interface condition.