Revealing of magnetic domains of strong bulk anisotropic permanent magnets via magnetic force microscopy

A novel fixture is provided for revealing magnetic domains of strong bulk permanent magnets in remanent state using magnetic force microscopy (MFM). Using this, the magnetic force lines outside the strong magnetic samples are introduced through a soft magnetic alloy with high permeability, giving rise to little perturbation between magnetic sample and MFM tips while scanning. Simulation results show that the demagnetized field over the studied surface is lowered about 300 times for a cuboid permanent magnet sample. Taking typical strong Sm2Co17-type sintered magnet as example, the true revealing of the magnetic domains via MFM further confirms that the method provided is feasible.