Magnetic Force Microscopy for Magnetic Recording and Devices

By coating a tip of a non-contacting scanning probe with a magnetic material, scanning probe microscopy can become sensitive to a stray field from the surface of magnetic materials and devices, magnetic force microscopy. The behaviour of such magnetic samples is well-known to be controlled by the formation and reversal of magnetic domains, each of which has a uniform magnetic moment separated by a region with moment rotation, a magnetic domain wall, to minimise total energy. The formation of the magnetic domains and walls is dependent upon size changes even at an atomic scale, which defines a critical length scale in much more strict manner than a semiconductor and metallic sample. It is therefore important to image magnetic domain structures of the magnetic samples precisely to reveal the corresponding performance. Magnetic force microscopy is one of the most convenient techniques for magnetic imaging with nanometric resolution as detailed in this chapter.