Nanostructured MnGa films on Si/SiO2 with 20.5 kOe room temperature coercivity

Nanostructured Mn67Ga33 films exhibiting high room temperature coercivity (HC = 20.5 kOe) have been prepared by sputtering onto thermally oxidized Si substrates. Both the morphology and the coercivity of the films can be tuned by varying the growth parameters. The low deposition rate film, sputtered at a reduced power and working pressure, demonstrates a discontinuous island-like growth and the highest HC. The large HC is linked to the presence of the high anisotropy DO22 Mn3Ga phase and the single domain character of the exchange isolated, dipolar interacting, single crystal islands.