Magnetic and structural properties of Mn-Ga thin films

uA systematic experimental work has been conducted to understand the magnetic properties of Mn-Ga thin films. Multilayer structured thin films of [MnGa 2 nm/Mn x nm]x25 (x = 0.2 similar to 3.5, which corresponds to Mn at%56 similar to 86) were sputter-deposited onto silica glass substrates, followed by annealing in vacuum. It is found that the magnetic properties strongly depend on x. For x = 0.5, the high magnetization values are found, where the nanocrystalline L1(0) structure is present. The samples with x = 2.0-3.0 exhibit the coercivity H-c higher than 10 kOe at room temperature where the nanocrystalline D0(22) structures are found to form. The correlation between the magnetic anisotropy constant K and saturation magnetization M-s is also discussed. The nth power dependence of magnetic anisotropy constant K on M-s is found, where the values of n are 7.8 and 1.9 for x = 0.5 and 2.5, respectively. The present result of the power dependence of n equals about 8 for the L1(0) MnGa suggests that the magnetic anisotropy in a nanocrystalline L1(0) MnGa phase is much different from the ordered FePt phase. On the other hand, the power dependence of the D0(22) nanocrystalline phase suggests the two-ion mechanism. (C) 2016 Author(s).