Near-surface magnetic properties of CoFeAlO thin films

We present here, the results of a thorough study of the surface and magnetic properties of as-deposited and annealed Co-Fe-Al-O thin films using the magneto-optical Kerr effect technique. An increase in magnetic anisotropy was found in the near-surface region of the film, which is ascribed to the microstructural change occurring in this region. It is found that the partial pressure of oxygen caused considerable changes in the transverse Kerr effect spectra and hence the magnetic properties of the thin films. The step-like magnetization behavior was observed at a light wavelength of 310 nm while it disappeared for higher wavelengths of light. The step-like magnetization phenomenon is due to the magnetic wall displacement process of each fracturized domain in the surface region.