Application of the colloid-SEM method to observations on perpendicular magnetic recordings

The colloid-SEM method, a modified Bitter method using SEM, has been applied to observations on perpendicular magnetic recordings. The recording media were vacuum-evaporated Co-24.0 wt%Cr films of about 2000 Å in thickness with recording densities of 150 to 300 kBPI. It is found that in order to obtain clear recorded patterns a magnetic field less than 500 Oe must be applied perpendicularly to the film plane during the deposition of a magnetite colloidal solution. Recorded patterns obtained by this method are shown and conditions for better patterns by the colloid-SEN method are suggested.