MAGNETIC CHARACTERIZATION OF THIN-FILM RECORDING MEDIA

In this paper the basic magnetic characterisation techniques for thin film recording media are critically examined in relation to the requirements for modern high storage density materials. The applicability and usefulness of remanence curves for the characterisation of thin film media is discussed together with the recently developed DELTAI (H) technique. The origins of the relation between these measurements and cooperative reversal are presented together with improved data showing the correlation between DELTAI (H) and noise. This discussion is extended to include the time dependent phenomena and in particular the activation volume, including the effects of intergranular coupling. Data is presented to show these effects in both single layer alloy films and laminated systems and the implications for ultimate recording density discussed.