Modifying magnetization behavior of magnetic films utilizing surface grooved grating patterns

The film-based magnetic sensors possess prominent superiorities in miniaturization and integration. Because of the presence of shape demagnetization, the magnetic film effective permeability is dramatically degraded, restricting the performance improvement of planar magnetic sensors. This study reports an efficacious approach to compensate for the shape demagnetization and actively increase effective permeability by introducing grooved grating patterns on a magnetic film surface. The grating patterned films are demonstrated that the maximum values of effective permeability and its variation rate with a magnetic field are increased by 446.03% and 606.77% compared with the same thickness smooth film. It is experimentally demonstrated that the magnetic behavior of the patterned film is modified. The magnetization curves of grooved films exhibit two magnetization rising stages. In addition, the anisotropy of the grooved films can be also tuned through the shape anisotropy of the gratings. Effective permeability and anisotropy field can be enhanced together by grooved grating patterns, which cannot be realized in smooth magnetic films. These results indicate that the surface grating etching strategy provides an effective method to modify the film magnetization behaviors. The grating-patterned films have enormous potential for ultra-sensitive and wide-range micro-magnetic sensors.