Studies of the micromagnetic structure of recorded tracks in MET

The micromagnetic structure of CoNi 80/20 films used in metal evaporated tape for magnetic recording has been studied using the techniques of Lorentz electron microscopy and in particular that of differential phase contrast imaging. In contrast to stationary head recording, we have found a strong component of transverse magnetisation associated with helical scan recording. At high recording densities the bit cells contain a number of reversed domains in the track direction whilst at low recording densities the transitions are generally zig-zag in character. Even at high recording densities the transverse component remains continuous and in helical recording very sharp transitions result for this component.