Magneto-optical properties of obliquely evaporated Ni films

Longitudinal magneto-optical Kerr effect (MOKE) configuration and scanning electron microscopy (SEM) were used to investigate the effects of deposition angle, α on magnetic properties and morphology of obliquely evaporated Ni films. The results show that the angle of deposition has a critical effect on the magnetic anisotropy of the films. These effects are due to the microstructure of the films, which is controlled by the angle of deposition with respect to the sample normal. The results show the presence of shape anisotropy governing the demagnetization of the magnetic fields. The anisotropy, coercivity and squareness of the hysteresis loops increased with an increase in α of the vapour flux. These properties and surface roughness became marked for off-normal deposition angles larger than 50°. At low αs, the easy axis of magnetization lay perpendicular to the incidence plane. At large αs the easy axis changed parallel to the incidence plane. The results may be quantitatively understood from the presence of an inclined columnar microstructure with shape anisotropy governing the demagnetization of the magnetic fields.