Magnetic Anisotropy and Reversal in Epitaxial FeGa/MgO(001) Films Deposited at Oblique Incidence

We have epitaxially deposited FeGa films onto MgO(001) substrates at an oblique angle κ varying from 0 to 45 and systematically investigated their magnetization reversal. The square and two-step hysteresis loops were observed in the samples deposited at κ = 0 and 15. The reversed two-step and three-step hysteresis loops were observed in the samples deposited at κ = 30 and 45, in which a strong uniaxial magnetic anisotropy Ku was induced by the oblique deposition. A model based on domain wall (DW) nucleation and propagation was employed to quantitatively describe the angular-dependent behaviors of FeGa epitaxial films, which indicates that, for the samples deposited with increasing κ, the 180 magnetic transitions occurring in the magnetic field orientation between 45 and 45 gradually change from the two successive 90 DW nucleations to the 180 DW nucleation.