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 φ 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 φ = 0° and 15°. The reversed two-step and three-step hysteresis loops were observed in the samples deposited at φ = 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 φ, 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.