REVERSIBLE CHANGES DURING REMANENT MAGNETIZATION AND DEMAGNETIZATION PROCESSES IN PARTICULATE AND THIN-FILM RECORDING MEDIA

The reversible magnetisation relaxation has been investigated during remanent magnetisation and demagnetisation processes in various recording media and has been found to exhibit a maximum around remanent coercivity in particulate media. This can be explained in terms of particle switching and a computer model based on coherent rotation gives a good qualitative fit. The magnitude of the reversible effects during the various remanent processes are related and observed second order effects are discussed in the context of interactions. Longitudinal thin film media with different film structures have also been investigated and large differences in their reversible behaviour are described.