High density recorded patterns observed by high-resolution Bitter scanning electron microscope method

We have developed a new and versatile method for observation of fine domain structures in ferromagnetic specimens. In this method, which we call here the high-resolution Bitter scanning electron microscope (HRBS) method, ferromagnetic fine particles as small as 20 nm are fabricated by sputtering, and are subsequently deposited on the surface of ferromagnetic samples to be investigated. The particles form very faithful domain patterns reflecting the leakage field distribution from the samples. We have applied this method to several magnetic and magneto-optic high density recording media, and have successfully observed the bit patterns at a recording density of 300 kFCl (bit length similar to 80 nm). Moreover, we have confirmed that the HRBS method is also effective in investigating the magnetized states within each recording bit. (C) 1996 American Institute of Physics.