Orientation-sensitive magnetic force microscopy for future probe storage applications

A focused ion beam process was utilized to physically define a “point dipole” magnetic force microscopy (MFM) tip with cylindrical dimensions as small as 50 nm in diameter and 10 nm in height. By controlling the preferred orientation of the magnetization, it is possible to define directional sensitivity. The preferred orientation is controlled either by choosing a proper magnetic material with preferred crystalline anisotropy or by applying a sufficiently strong external magnetic field. The signal selectivity with respect to the imaged field orientation allows more direct information to be obtained from the imaged object, as compared to the information obtained from the same object when using a conventional MFM tip.